FREE ENGLISH MRCOOL MGM95SE045B3XA (01) PDF USER GUIDE
FREE ENGLISH MRCOOL MGM95SE045B3XA (01) PDF USER MANUAL
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MRCOOL MGM95SE045B3XA (01) PDF SUMMARY:
What should be done if the equipment has shipping damage?
If any damage is found, immediately contact the last carrier.
What should you do before installing the furnace?
Consult authorities having jurisdiction before installation.
What general recommendations must be considered when installing one of these furnaces?
- Place the furnace as close to the center of the air distribution system as possible.
- The furnace should also be located close to the vent termination point.
- When the furnace is installed in non-direct vent applications, do not install the furnace where drafts might blow directly into it. This could cause improper combustion and unsafe operation.
- When the furnace is installed in non-direct vent applications, do not block the furnace combustion air opening with clothing, boxes, doors, etc. Air is needed for proper combustion and safe unit operation.
- When the furnace is installed in an attic or other insulated space, keep insulation away from the furnace.
- When the furnace is installed in an unconditioned space, consider provisions required to prevent freezing of condensate drain system.
What are the stipulations for gas furnaces in the Commonwealth of Massachusetts?
- Gas furnaces shall be installed by a licensed plumber or fitter only.
- The gas cock must be ”T handle" type.
- When a furnace is installed in an attic, the passageway to and service area surrounding the equipment shall be floored.
What should you avoid exposing to the combustion air supply?
- Permanent wave solutions
- Chlorinated waxes and cleaners
- Chlorine base swimming pool chemicals
- Water softening chemicals
- De-icing salts or chemicals
- Carbon tetrachloride
- Halogen type refrigerants
- Cleaning solvents (such as perchloroethylene)
- Printing inks, paint removers, varnishes, etc.
- Hydrochloric acid
- Cements and glues
- Antistatic fabric softeners for clothes dryers
- Masonry acid washing materials
What should you do if this unit is being installed in an application with combustion air coming in from a space serviced by an exhaust fan, power exhaust fan, or other device which may create a negative pressure in the space?
Take care when sizing the inlet air opening. The inlet air opening must be sized to accommodate the maximum volume of exhaust air as well as the maximum volume of combustion air required for all gas appliances serviced by this space.
What should you do before the furnace is placed into operation for units with 1/2 hp & 3/4 hp blower motor?
The bolt and washer must be removed before the furnace is placed into operation. After the bolt and washer have been removed, the rigid leg will not touch the blower housing.
What should you consider for upflow applications?
Select a location that allows for the required clearances that are listed on the unit nameplate. Also consider gas supply connections, electrical supply, vent connection, condensate trap and drain connections, and installation and service clearances [24 inches (610 mm) at unit front].
How should the unit be tilted for upflow applications?
The unit must be level from side to side. Tilt the unit slightly (maximum 1/2 in. from level) from back to front to aid in the draining of the heat exchanger.
What should you never allow to enter the return air system or air in the living space?
Combustion and flue products must never be allowed to enter the return air system or air in the living space. Use sheet metal screws and joint tape to seal return air system to furnace.
What should you do in platform installations with furnace return?
The furnace should be sealed airtight to the return air plenum.
What should a base provide?
The base must provide a stable support and an airtight seal to the furnace. Allow absolutely no sagging, cracks, gaps, etc.
What should you do if the furnace is installed on a platform with bottom return?
Make an airtight seal between the bottom of the furnace and the platform to ensure that the furnace operates properly and safely. The furnace is equipped with a removable bottom panel to facilitate installation.
What should you do for installations that require side return air?
Cut the furnace cabinet at the maximum dimensions shown.
What do furnace applications which include side return air and a condensate trap installed on the same side of the cabinet require?
Furnace applications which include side return air and a condensate trap installed on the same side of the cabinet (trap can be installed remotely within 5 ft.) require either a return air base or field-fabricated transition to accommodate an optional IAQ accessory taller than 14.5".
How should you position the unit for horizontal applications?
Do not install the furnace on its front or its back.
What should you keep in mind when selecting a location for a horizontal unit?
Select location for unit keeping in mind service and other necessary clearances.
How do you construct a raised platform for horizontal applications?
Construct a raised wooden frame and cover frame with a plywood sheet. If unit is installed above finished space, fabricate an auxiliary drain pan to be installed under unit. Set unit in drain pan. Leave 8 inches for service clearance below unit for condensate trap.
How do you install a proper support platform in a crawl space for horizontal applications?
When installing the unit in a crawl space, a proper support platform may be created using cement blocks.
How should you route an auxiliary drain line?
Route auxiliary drain line so that water draining from this outlet will be easily noticed by the homeowner.
What should you do if it is necessary to run the condensate line into a condensate pump to meet drain line slope requirements?
- The pump must be rated for use with condensing furnaces.
- Protect the condensate discharge line from the pump to the outside to avoid freezing.
What should you do after routing the auxiliary drain line?
Continue with exhaust, condensate and intake piping installation according to instructions.
How is return air brought in through a furnace installed in the horizontal position?
Return air may be brought in only through the end of a furnace installed in the horizontal position. The furnace is equipped with a removable bottom panel to facilitate installation.
What must be in place whenever the unit is operating?
A filter must be in place whenever the unit is operating.
What standards should you use to size and install the supply and return air duct system?
Use industry approved standards to size and install the supply and return air duct system. This will result in a quiet and low-static system that has uniform air distribution.
What should be installed in the supply air duct if the furnace is installed without a cooling coil?
If the furnace is installed without a cooling coil, a removable access panel should be installed in the supply air duct. The access panel should be large enough to permit inspection (by reflected light) of the heat exchanger for leaks after the furnace is installed.
What must always be in place when the furnace is operating, and what must it not allow?
The furnace access panel must always be in place when the furnace is operating and it must not allow leaks into the supply air duct system.
What should you use to ensure a tight seal between the plenum and the furnace cabinet?
Use fiberglass sealing strips, caulking, or equivalent sealing method between the plenum and the furnace cabinet to ensure a tight seal. If a filter is installed, size the return air duct to fit the filter frame.
What must all cementing of joints be done according to?
All cementing of joints should be done according to the specifications outlined in ASTM D 2855.
What may be used to secure the intake pipe to the connector?
A sheet metal screw may be used to secure the intake pipe to the connector, if desired. Use a drill or self tapping screw to make a pilot hole.
What steps should you follow for joint cementing procedure?
- Measure and cut vent pipe to desired length.
- Debur and chamfer end of pipe, removing any ridges or rough edges. If end is not chamfered, edge of pipe may remove cement from fitting socket and result in a leaking joint.
- Clean and dry surfaces to be joined.
- Test fit joint and mark depth of fitting on outside of pipe.
- Uniformly apply a liberal coat of PVC primer for PVC or use a clean dry cloth for ABS to clean inside socket surface of fitting and male end of pipe to depth of fitting socket.
- Promptly apply solvent cement to end of pipe and inside socket surface of fitting. Cement should be applied lightly but uniformly to inside of socket. Take care to keep excess cement out of socket. Apply second coat to end of pipe.
- Immediately after applying last coat of cement to pipe, and while both inside socket surface and end of pipe are wet with cement, forcefully insert end of pipe into socket until it bottoms out. Turn PVC pipe 1/4 turn during assembly (but not after pipe is fully inserted) to distribute cement evenly. Do not turn ABS or cellular core pipe.
- After assembly, wipe excess cement from pipe at end of fitting socket. A properly made joint will show a bead around its entire perimeter. Any gaps may indicate an improper defective assembly due to insufficient solvent.
- Handle joints carefully until completely set.
What should you conduct when an existing furnace is removed from a venting system commonly run with separate gas appliances?
Conduct the following test while each appliance is operating and the other appliances (which are not operating) remain connected to the common venting system. If the venting system has been installed improperly, you must correct the system as indicated in the general venting requirements section.
What steps shall be followed for each appliance connected to the venting system being placed into operation, while all other appliances connected to the venting system are not in operation?
- Seal any unused openings in the common venting system.
- Inspect the venting system for proper size and horizontal pitch. Determine that there is no blockage, restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.
- Close all building doors and windows and all doors between the space in which the appliances remaining connected to the common venting system are located and other spaces of the building. Turn ON clothes dryers and any appliances not connected to the common venting system. Turn ON any exhaust fans, such as range hoods and bathroom exhausts, so they will operate at maximum speed. Do not operate a summer exhaust fan. Close fireplace dampers.
- Follow the lighting instructions. Turn ON the appliance that is being inspected. Adjust the thermostat so that the appliance operates continuously.
- After the main burner has operated for 5 minutes, test for leaks of flue gases at the draft hood relief opening. Use the flame of a match or candle.
- After determining that each appliance connected to the common venting system is venting properly, (step 3) return all doors, windows, exhaust fans, fireplace dampers, and any other gas burning appliances to their previous mode of operation.
- If a venting problem is found during any of the preceding tests, the common venting system must be modified to correct the problems.
What should you check if this gas furnace replaces a furnace which was commonly vented with another gas appliance?
If this gas furnace replaces a furnace which was commonly vented with another gas appliance, the size of the existing vent pipe for that gas appliance must be checked. Without the heat of the original furnace flue products, the existing vent pipe is probably oversized for the single water heater or other appliance. The vent should be checked for proper draw with the remaining appliance.
What guidelines should you follow for exhaust piping?
- In areas where piping penetrates joist or interior walls, hole must be large enough to allow clearance on all sides of pipe through center of hole using a hanger.
- When furnace is installed in a residence where unit is shut down for an extended period of time, such as a vacation home, make provisions for draining condensate collection from trap and lines.
- Route piping to outside of structure. Continue with installation following instructions given in piping termination section.
What should you do in horizontal applications when transitioning to exhaust pipe larger than 2"?
In horizontal applications, transition to exhaust pipe larger than 2" must be made in vertical runs of the pipe. A 2" elbow must be added before the pipe is transitioned to any size larger than 2". This elbow must be added to the elbow count used to determine acceptable vent lengths.
What should you do if you need assistance in sizing vent pipe in applications which permit the use of several different sizes of vent pipe?
Contact for assistance in sizing vent pipe in these applications.
What should you do in applications which permit the use of several different sizes of vent pipe?
It is acceptable to use any pipe size which fits within the guidelines allowed.
How should all horizontal runs of exhaust pipe slope?
All horizontal runs of exhaust pipe must slope back toward unit. A minimum of 1/4" (6 mm) drop for each 12" (305 mm) of horizontal run is mandatory for drainage.
What information is needed to find the max pipe length?
- Standard or Concentric
- Intake or Exhaust
- Furnace capacity
- Which termination
- Which needs most elbows
- How many elbows
- Desired pipe size
- What is the altitude
What should not be used in exhaust or intake terminations?
Do not use screens or perforated metal in exhaust or intake terminations. Doing so will cause freeze-ups and may block the terminations.
What must be followed when intake air will be drawn into the furnace from the surrounding space?
In non-direct vent applications, when intake air will be drawn into the furnace from the surrounding space, the indoor air quality must be considered and guidelines listed in Combustion, Dilution and Ventilation Air section must be followed.
What should you do when installing the unit in Direct Vent applications, where combustion air is taken from outdoors and flue gases are discharged outdoors?
Follow the next two steps when installing the unit in Direct Vent applications, where combustion air is taken from outdoors and flue gases are discharged outdoors. The provided air intake screen must not be used in direct vent applications (outdoors).
- Use transition solvent cement or a sheet metal screw to secure the intake pipe to the inlet air connector.
- Route piping to outside of structure. Continue with installation following instructions given in general guide lines for piping terminations and in intake and exhaust piping terminations for direct vent sections. Refer to through for pipe sizes.
What should you do when installing the unit in Non-Direct Vent applications where combustion air is taken from indoors and flue gases are discharged outdoors?
Follow the next two steps when installing the unit in Non-Direct Vent applications where combustion air is taken from indoors and flue gases are discharged outdoors.
- Use field-provided materials and the factory-provided air intake screen to route the intake piping. Maintain a minimum clearance of 3" (76 mm) around the air intake opening. The air intake opening (with the protective screen) should always be directed forward or to either side in the upflow position, and either straight out or downward in the horizontal position.
- The air intake piping must not terminate too close to the flooring or a platform. Ensure that the intake air inlet will not be obstructed by loose insulation or other items that may clog the debris screen.
- If intake air is drawn from a ventilated attic or ventilated crawlspace the exhaust vent length must not exceed those listed. If 3" diameter pipe is used, reduce to 2" diameter pipe at the termination point to accommodate the debris screen.
What should be used to secure the intake pipe to the connector, if desired?
Use a sheet metal screw to secure the intake pipe to the connector, if desired.
What should you do if this unit is being installed in an application with combustion air coming in from a space serviced by an exhaust fan, power exhaust fan, or other device which may create a negative pressure in the space?
If this unit is being installed in an application with combustion air coming in from a space serviced by an exhaust fan, power exhaust fan, or other device which may create a negative pressure in the space, take care when sizing the inlet air opening. The inlet air opening must be sized to accommodate the maximum volume of exhaust air as well as the maximum volume of combustion air required for all gas appliances serviced by this space.
What should you refer to in the absence of local codes?
In both Non-Direct Vent and Direct Vent applications, the vent termination is limited by local building codes. In the absence of local codes, refer to the current National Fuel Gas Code ANSI 2223-1/NFPA 54 in U.S.A., and current CSA-B149 Natural Gas and Propane Installation Codes in Canada for details.
How should the termination be positioned?
Position termination according to location. In addition, position termination so it is free from any obstructions and 12" above the average snow accumulation.
What care must be taken at vent termination?
At vent termination, care must be taken to maintain protective coatings over building materials (prolonged exposure to exhaust condensate can destroy protective coatings).
What is recommended for the exhaust outlet location?
It is recommended that the exhaust outlet not be located within 6 feet (1.8 m) of a condensing unit because the condensate can damage the painted coating.
What may be necessary in extreme cold climate areas?
In extreme cold climate areas, 3/4" (19 mm) Armaflex or equivalent may be necessary. Insulation on outside runs of exhaust pipe must be painted or wrapped to protect insulation from deterioration.
What should you do during extremely cold temperatures?
During extremely cold temperatures, below approximately 20° F (6. 7° C), units with long runs of vent pipe through unconditioned space, even when insulated, may form ice in the exhaust termination that prevents the unit from operating properly. Longer run times of at least 5 minutes will alleviate most icing problems. Also, a heating cable may be installed on exhaust piping and termination to prevent freeze-ups.
What should not be used in exhaust terminations?
Do not use screens or perforated metal in exhaust terminations. Doing so will cause freeze-ups and may block the terminations.
What is the minimum allowed distance between the combustion air intake inlet and the exhaust outlet of other appliances, in accordance to CSA International B149 installation codes?
In accordance to CSA International B149 installation codes, the minimum allowed distance between the combustion air intake inlet and the exhaust outlet of other appliances shall not be less than 12 inches (305 mm).
What should be done if insulation is required in an unconditioned space?
If insulation is required in an unconditioned space, it must be located on the pipe closest to the furnace.
What should be avoided to make sure there is no recirculation of exhaust back into intake pipe?
Care must be taken to avoid recirculation of exhaust back into intake pipe.
How far exhaust piping may extend for sidewall exit, on field supplied terminations?
On field supplied terminations for sidewall exit, exhaust piping may extend a maximum of 12 inches (305 mm) for 2" PVC and 20 inches (508 mm) for 3" (76 mm) PVC beyond the outside wall. Intake piping should be as short as possible.
What should be used to protect the wall surface if flue gases may impinge on the building material?
If any vent termination is used and the flue gases may impinge on the building material, a corrosion-resistant shield (minimum 24 inches square) must be used to protect the wall surface. All seams, joints, cracks, etc. in the affected area should be sealed using an appropriate sealant.
Where may intake and exhaust pipes be routed?
Intake and exhaust pipes may be routed either horizontally through and outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof is preferred.
Are intake and exhaust terminations required to be in the same pressure zone?
Intake and exhaust terminations are not required to be in the same pressure zone.
How should intake and exhaust pipes be placed at termination end?
Intake and exhaust pipes should be placed as close together as possible at termination end. Minimum separation is 3" (76 mm) on roof terminations and 6" (152 mm) on sidewall terminations.
How should the intake piping terminate on roof terminations?
On roof terminations, the intake piping should terminate straight down using two 90° elbows.
How must exhaust piping terminate?
Exhaust piping must terminate straight out or up. A reducer may be required on the exhaust piping at the point where it exits the structure to improve the velocity of exhaust away from the intake piping.
How do you Field Fabricate a Wall Termination?
- Clearance above grade or average snow accumulation for a 2" vent pipe is 12” (305 mm) Min, and for a 3" vent pipe is 12” (305 mm) Min.
- Horizontal separation between intake and exhaust for a 2" vent pipe is 6” (152 mm) Min. 24” (610 mm) Max, and for a 3" vent pipe is 6” (152 mm) Min. 24” (610 mm) Max.
- Minimum from end of exhaust to inlet of intake for a 2" vent pipe is 9” (227 mm) Min, and for a 3" vent pipe is 12” (305 mm) Min. 20” (508 mm) Max.
- Exhaust pipe length for a 2" vent pipe is 12” (305 mm) Min. 16” (405 mm) Max, and for a 3" vent pipe is 6” (152 mm) Max.
- Wall support distance from the top of each pipe (intake/exhaust) is 6” (152 mm) Max.
What are the details of exhaust piping terminations for non-direct vent roof termination kit?
- Exhaust pipes may be routed either horizontally through an outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof is preferred.
- Exhaust piping must terminate straight out or up. The termination pipe must be sized as listed in Table 7. The specified pipe size ensures proper velocity required to move the exhaust gases away from the building.
- On field-supplied terminations for side wall exit, exhaust piping may extend a maximum of 12 inches (305 mm) for 2" PVC and 20" (508 mm) for 3" (76 mm) PVC beyond the outside wall.
- If exhaust piping must be run up a sidewall to position above snow accumulation or other obstructions, piping must be supported every 24" (610 mm) as shown in Figure 47. When exhaust piping must be run up an outside wall, any reduction in exhaust pipe size must be done after the final elbow.
How should horizontal runs of exhaust pipe be installed with an exhaust through a crawl space?
All horizontal runs of exhaust pipe must slope back toward the kit a minimum of 1/4" (6mm) for each 12" (305mm) to ensure drainage.
How do you install condensate piping?
- Determine which side condensate piping will exit the unit, location of trap, field-provided fittings, and length of PVC pipe required to reach the available drain.
- Use a large flat head screwdriver or a 1/2" drive socket extension and remove the plug (Figure 52) from the cold end header box at the appropriate location on the side of the unit. Install provided 3/4 NPT street elbow fitting into cold end header box. Use Teflon tape or appropriate pipe dope.
- Install the cap over the clean out opening at the base of the trap. Secure with clamp.
- Install drain trap using appropriate PVC fittings, glue all joints. Glue the provided drain trap as shown in Figure 59. Route the condensate line to an open drain. Condensate line must maintain a 1/4" downward slope from the furnace to the drain.
- Figure 55 and Figure 56 show the furnace and evaporator coil using a separate drain. If necessary, the condensate line from the furnace and evaporator coil can drain together. See Figure 57 and Figure 58.
- If the unit will be started immediately upon completion of installation, prime trap per procedure outlined in Unit Start-Up section.
What should you do when connecting a gas supply?
When connecting the gas supply, factors such as length of run, number of fittings, and furnace rating must be considered to avoid excessive pressure drop. Table 8 lists recommended pipe sizes for typical applications.
What are some gas piping guidelines?
- Gas piping may be routed into the unit through either the left or right-hand side. Supply piping enters into the gas valve from the side of the valve as shown in Figure 61. Move Bellows grommet to the side which gas line enters. Ensure the opposite gas line hole is plugged with supplied plug.
- Gas piping must not run in or through air ducts, clothes chutes, chimneys or gas vents, dumb waiters, or elevator shafts. Center gas line through piping hole. Gas line should not touch the side of the unit.
- Piping should be sloped 1 /4 " per 15 feet (6 mm per 5.6 m) upward toward the gas meter from the furnace. The piping must be supported at proper intervals, every 8 to 10 feet (2.44 to 3.05 m), using suitable hangers or straps. Install a drip leg in vertical pipe runs to serve as a trap for sediment or condensate.
- A 1/8" N.P.T. plugged tap or pressure post is located on the gas valve to facilitate test gauge connection.
- In some localities, codes may require installation of a manual main shut-off valve and union (furnished by installer) external to the unit. The union must be of the ground joint type.
What should you do after gas piping is completed?
After gas piping is completed, carefully check all piping connections (factory and field installed) for gas leaks. Use a leak-detecting solution or other preferred means.
How should electrostatic discharge (ESD) precautions and procedures be followed?
Neutralize electrostatic charge by touching hand and all tools on an unpainted unit surface, such as the gas valve or blower deck, before performing any service procedure.
How do you install the interior make-up box?
The unit is equipped with a field makeup box that may be moved to the right side of the furnace to facilitate installation. Seal unused openings on the left side with plugs removed from the right side. Secure the excess wire to the existing harness to protect it from damage.
What are some electrical wiring guidelines?
- The power supply wiring must meet Class I restrictions and be protected by either a fuse or circuit breaker. Select circuit protection and wire size according to unit nameplate.
- Install a separate (properly sized) disconnect switch near the furnace so that power can be turned off for servicing.
- Before connecting the thermostat, check to make sure the wires will be long enough for servicing at a later date. Make sure that the thermostat wire is long enough to facilitate future removal of the blower for service.
- Complete the wiring connections to the equipment. Use the provided unit wiring diagram and the field wiring diagram shown in Figure 66. Use 18 gauge wire or larger that is suitable for Class II rating for thermostat connections.
- Electrically ground the unit according to local codes or, in the absence of local codes, according to the current National Electric Code (ANSI/HFPA No. 70) for the USA and current Canadian Electric Code Part 1 (CSA standard C22.1) for Canada. A green ground wire is provided in the field makeup box.
- The gas furnace contains electronic components that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.
How to use the room thermostat?
- Install the room thermostat according to the instructions provided with the thermostat. See Figure 65 for thermostat designations.
- When the thermostat is set to “FAN ON”, the indoor blower will run continuously on the fan speed when there is no cooling or heating demand. See Table 14 for allowable continuous circulation speeds.
- When the furnace is running in the heating mode, the indoor blower will run on the heating speed.
- When there is a cooling demand, the indoor blower will run on the cooling speed.
What are the voltage requirements for generator use?
- The furnace requires 120 volts ± 10% (Range: 108 volts to 132 volts)
- The furnace operates at 60 Hz ± 5% (Range: 57 Hz to 63 Hz)
- The furnace integrated control requires both proper polarity and proper ground. Both polarity and proper grounding should be checked before attempting to operate the furnace on either permanent or temporary power.
- The generator should have a waveform distortion of less than 5% THD (total harmonic distortion).
How do you place the furnace into operation?
- Read the safety information at the beginning of this section.
- Set the thermostat to the lowest setting.
- Turn OFF all electrical power to the unit.
- This furnace is equipped with an ignition device which automatically lights the burners. Do not try to light the burners by hand.
- Remove the upper access panel.
- Move gas valve switch to OFF. See Figure 69.
- Wait five minutes to clear out any gas. If you then smell gas, Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions. If you do not smell gas go to next step.
- Move gas valve switch to ON. See Figure 69.
- Replace the upper access panel.
- Turn on all electrical power to the unit.
- Set the thermostat to the desired setting.
When the unit is initially started, steps 1 through 11 may need to be repeated to purge air from the gas line.
What should you check if the appliance will not operate?
- Is the thermostat calling for heat?
- Are access panels securely in place?
- Is the main disconnect switch closed?
- Is there a blown fuse or tripped breaker?
- Is the filter dirty or plugged? Dirty or plugged filters will cause the limit control to shut the unit off.
- Is gas turned on at the meter?
- Is the manual main shut-off valve open?
- Is the internal manual shut-off valve open?
- Is the unit ignition system in lockout? If the unit locks out again, inspect the unit for blockages.
What is the heating sequence of operation?
- When the thermostat calls for heat, the combustion air inducer starts.
- Combustion air pressure switch proves blower operation. The switch is factory set and requires no adjustment.
- After a 15-second pre-purge, the hot surface ignitor energizes.
- After a 20-second ignitor warm-up period, the gas valve solenoid opens. A 4-second “Trial for Ignition” period begins.
- Gas is ignited, flame sensor proves the flame, and the combustion process continues.
- If the flame is not detected after the first ignition trial, the ignition control will repeat steps 3 and 4 four more times before locking out the gas valve. The ignition control will then automatically repeat steps 1 through 6 after 60 minutes. To interrupt the 60-minute period, move the thermostat from “Heat” to “OFF” then back to “Heat”. The heating sequence then restarts at step 1.
How do you perform a Gas Pressure Adjustment Gas Flow (Approximate)?
- Furnace should operate at least 5 minutes before checking gas flow. Determine time in seconds for two revolutions of gas through the meter. (Two revolutions assures a more accurate time.) Divide by two and compare to time in Figure 68. If manifold pressure matches Table 11 and rate is incorrect, check gas orifices for proper size and restriction. Remove temporary gas meter if installed.
- To obtain an accurate reading, shut off all other gas appliances connected to the meter.
How do you perform a Supply Pressure Measurement?
- When testing supply gas pressure, use the 1/8" N.P.T. plugged tap or pressure post located on the gas valve to facilitate test gauge connection. See Figure 69.
- Check gas line pressure with unit firing at maximum rate. Low pressure may result in erratic operation or underfire. High pressure can result in permanent damage to the gas valve or overfire.
- On multiple-unit installations, each unit should be checked separately, with and without other units operating. Supply pressure must fall within the range listed in Table 11.
How do you perform a Manifold Pressure Measurement?
- Remove the threaded plug from the outlet side of the gas valve and install a field-provided barbed fitting. Connect to a manometer to measure manifold pressure.
- Start unit and allow 5 minutes for the unit to reach steady state.
- While waiting for the unit to stabilize, observe the flame. The flame should be stable and should not lift from the burner. Natural gas should burn blue.
- After allowing the unit to stabilize for 5 minutes, record manifold pressure and compare to the value given in Table 11.
- Shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to remove the barbed fitting and replace the threaded plug.
How do you ensure proper combustion?
- The furnace should operate for a minimum of 15 minutes with the correct manifold pressure and gas flow rate before checking combustion.
- Take a combustion sample beyond the flue outlet and compare it to the tables below.
- The maximum carbon monoxide reading should not exceed 100 ppm.
What steps should be followed for Testing for Proper Venting and Sufficient Combustion Air for Non-Direct Vent Applications?
The following steps shall be followed for each appliance connected to the venting system being placed into operation, while all other appliances connected to the venting system are not in operation:
- Seal any unused openings in the venting system.
- Visually inspect the venting system for proper size and horizontal pitch. Determine there is no blockage or restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.
- To the extent that it is practical, close all building doors and windows and all doors between the space in which the appliances connected to the venting system are located and other spaces of the building.
- Close fireplace dampers.
- Turn on clothes dryers and any appliances not connected to the venting system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they will operate at maximum speed.
- Follow the lighting instruction to place the appliance being inspected into operation. Adjust thermostat so appliance will operate continuously.
- Use the flame of a match or candle to test for spillage of flue gases at the draft hood relief opening after 5 minutes of main burner operation.
- If improper venting is observed during any of the above tests, the venting system must be corrected or sufficient combustion/makeup air must be provided. The venting system should be resized to approach the minimum size as determined by using the appropriate tables in appendix G in the current standards of the National Fuel Gas Code ANSl-2223.1/NPFA 54 in the U.S.A., and the appropriate Natural Gas and Propane appliances venting sizing tables in the current standard of the CSA-B149 Natural Gas and Propane Installation Codes in Canada.
- After determining that each appliance remaining connected to the common venting system properly vents when tested as indicated in step 3, return doors, windows, exhaust fans, fireplace dampers, and any other gas-burning appliance to their previous condition of use.
Where is the primary limit located and how is it adjusted?
The primary limit is located on the heating compartment vestibule panel. This limit is factory set and requires no adjustment.
Where are the flame rollout switches located and how are they adjusted?
These manually reset switches are located on the front of the burner box. These limits are factory set and require no adjustment.
Where is the pressure switch located and how is it adjusted?
The pressure switch is located in the heating compartment on the cold end header box. This switch checks for proper combustion air inducer operation before allowing ignition trial. The switch is factory set and must not be adjusted.
How do you adjust the temperature rise?
After the furnace has been started and supply and return air temperatures have been allowed to stabilize, check the temperature rise. If necessary, adjust the blower speed to maintain the temperature rise within the range shown on the unit nameplate. See Table 13 for allowable heating speeds. Increase the blower speed to decrease the temperature. Decrease the blower speed to increase the temperature rise. Failure to adjust the temperature rise may cause erratic limit operation.
How do you adjust the fan control?
The fan ON time of 30 seconds is not adjustable. The fan OFF delay (amount of time that the blower operates after the heat demand has been satisfied) may be adjusted by changing the jumper position across the five pins on the integrated control. The unit is shipped with a factory heat fan OFF setting of 90 seconds. The fan OFF delay affects comfort and is adjustable to satisfy individual applications. Adjust the fan OFF delay to achieve a supply air temperature between 90° and 110° F at the moment that the blower is de-energized. Longer OFF delay settings provide lower return air temperatures; shorter settings provide higher return air temperatures.
How do you set the thermostat heat anticipation?
Set the heat anticipator setting (if adjustable) according to the amp draw listed on the wiring diagram that is attached to the unit.
How do you change the blower speeds?
- Turn off electrical power to the furnace.
- Remove blower access panel.
- Disconnect existing speed tap at control board speed terminal. Termination of any unused motor leads must be insulated.
- Place unused blower speed tap on integrated control “PARK” terminal or insulate.
- Refer to blower speed selection chart on unit wiring diagram for desired heating or cooling speed. See Blower performance data beginning on the next page. See Table 13 for allowable heating speeds.
- Connect selected speed tap at control board speed terminal.
- Re-secure blower access panel.
- Turn on electrical power to the furnace.
- Recheck temperature rise.
What should a service technician check during an annual inspection?
A service technician should check the following items during an annual inspection. Power to the unit must be shut off for safety:
- Fresh air grilles and louvers (on the unit and in the room where the furnace is installed) – Must be open and unobstructed to provide combustion air.
- Burners – Must be inspected for rust, dirt, or signs of water.
- Vent pipe – Must be inspected for signs of water, cracked, damaged or sagging pipe, or disconnected joints.
- Unit appearance – Must be inspected for rust, dirt, signs of water, burnt or damaged wires, or components.
- Blower access door – Must be properly in place and provide a seal between the return air and the room where the furnace is installed.
- Return air duct – Must be properly attached and provide an air seal to the unit.
- Operating performance – Unit must be observed during operation to monitor proper performance of the unit and the vent system.
- Combustion gases – Flue products must be analyzed and compared to the unit specifications.
What do you do for winterizing and condensate trap care?
- Turn off power to the furnace.
- Have a shallow pan ready to empty condensate water.
- Remove the clean-out cap from the condensate trap and empty water. Inspect the trap then reinstall the clean out cap.
How do you clean the heat exchanger?
- Turn off electrical and gas supplies to the furnace.
- Remove the burner access panel.
- Mark all gas valve wires and disconnect them from valve.
- Remove gas supply line connected to gas valve.
- Remove sensor wire from flame sensor. Disconnect 2-pin plug from the igniter.
- Disconnect wires from flame rollout switches.
- Remove four burner assembly screws at the vestibule panel and remove gas valve /manifold and burner box as a single unit.
- If necessary, clean burners at this time. Follow procedures outlined in Burner Cleaning section.
- Remove the clean-out cap on trap and drain. Replace cap.
- Disconnect condensate drain line from the condensate trap. Remove condensate trap (it may be necessary to cut drain pipe). Remove the 1/2" NPT fitting from the cold end header box. Disconnect drain tubes from cold end header collector box.
- Disconnect condensate drain tubes from flue collar. Remove screws that secure flue collar in place. Remove flue collar. It may be necessary to cut the exiting exhaust pipe for removal of the fitting.
- Loosen two clamps from flexible no-hub exhaust collar.
- Disconnect the 2-pin plug from the combustion air inducer. Remove screws which secure combustion air inducer to collector box. Remove combustion air inducer assembly. Remove ground wire.
- Mark and disconnect all combustion air pressure tubing from cold end header collector box.
- Mark and remove wires from pressure switch. Remove pressure switch. Keep tubing attached to pressure switch.
- Remove electrical junction box from the side of the furnace.
- Remove blower access panel.
- Mark and disconnect any remaining wiring to heating compartment components. Disengage strain relief bushing and pull wiring and bushing through the hole in the blower deck.
- Remove the primary limit from the vestibule panel.
- Remove top cap screws to allow top cap to be tilted upward to allow clearance for removing heat exchanger.
- Remove two screws from the front cabinet flange at the blower deck. Spread cabinet sides slightly to allow clearance for removal of heat exchanger.
- Remove screws along vestibule sides and bottom which secure vestibule panel and heat exchanger assembly to cabinet. Remove two screws from blower rails which secure bottom heat exchanger flange. Remove heat exchanger from furnace cabinet.
- Back wash heat exchanger with soapy water solution or steam. If steam is used it must be below 275°F (135°C).
- Thoroughly rinse and drain the heat exchanger. Soap solutions can be corrosive. Take care to rinse entire assembly.
- Reinstall heat exchanger into cabinet making sure that the rear baffle of the heat exchanger assembly is nested under the support located at the rear of the cabinet. Remove the indoor blower to view this area through the blower opening.
- Re-secure the supporting screws along the vestibule sides.
- Reinstall blower assembly and reinstall two screws through rails.
- Reinstall cabinet screws on front flange at blower deck.
- Reinstall screws securing top cap.
- Reinstall the primary limit on the vestibule panel.
- Route heating component wiring through hole in blower deck and reinsert strain relief bushing.
- Reinstall pressure switch and reconnect pressure switch wiring.
- Carefully connect combustion air pressure switch hosing from pressure switch to proper stubs on cold end header collector box.
- Reinstall 1/2" NPT (if removed) in the cold end header box. Reconnect drain tubing to collector box.
- Reinstall condensate trap pipe. Reconnect condensate drain line to the condensate trap.
- Reinstall electrical junction box.
- Reinstall the combustion air inducer and flexible no hub connector. Reconnect the 2-pin plug to the wire harness.
- Reconnect drain tubes between flue collar and cold end header box.
- Secure burner assembly to vestibule panel using four existing screws. Burners are self-aligning to center of clam shells.
- Reconnect gas supply line to gas valve.
- Reconnect flame rollout switch wires.
- Reconnect sensor wire and reconnect 2 pin plug from igniter.
- Reconnect wires to gas valve.
- Replace the blower compartment access panel.
- Refer to instruction on verifying gas and electrical connections when reestablishing supplies.
- Follow lighting instructions to light and operate furnace for 5 minutes to ensure that heat exchanger is clean and dry and that furnace is operating properly.
- Replace heating compartment access panel.
How do you clean the burner assembly?
- Turn off gas and electrical power to the furnace. Remove heating compartment access panel.
- Disconnect the gas supply line from the gas valve.
- Disconnect and label wires from gas valve.
- Disconnect ignitor wiring at 2 circuit plug.
- Disconnect and label wires from rollout switch.
- Disconnect and label flame sensor wire.
- Disconnect and label ground wire from burner/manifold assembly.
- Remove four screws that secure burner/manifold assembly to vestibule. Remove the assembly and make note not to allow ignitor plate to dislodge from the assembly.
- Gently clean the face of the burners using the soft brush attachment on a vacuum cleaner. Visually inspect the inside of the burners and crossovers for any blockage caused by foreign matter. Remove any blockage.
- Reinstall the burner/manifold assembly using the existing four screws. Burners are self-aligning to center of clam shells.
- Reconnect ground wire.
- Reconnect flame sensor wire.
- Reconnect rollout switch wires.
- Reconnect ignitor wires.
- Reconnect gas valve wires.
- Reconnect gas supply line to gas valve.
- Refer to instructions on verifying gas and electrical connections when re-establishing supplies.
- Follow instructions to place furnace in operation. Run furnace 5 minutes to ensure burners are clean and operating correctly.
- Replace heating compartment access panel.
What should be checked during planned service?
A service technician should check the following items during an annual inspection. Power to the unit must be shut off for safety:
- Fresh air grilles and louvers (on the unit and in the room where the furnace is installed) – Must be open and unobstructed to provide combustion air.
- Burners – Must be inspected for rust, dirt, or signs of water.
- Vent pipe – Must be inspected for signs of water, cracked, damaged or sagging pipe, or disconnected joints.
- Unit appearance – Must be inspected for rust, dirt, signs of water, burnt or damaged wires, or components.
- Blower access door – Must be properly in place and provide a seal between the return air and the room where the furnace is installed.
- Return air duct – Must be properly attached and provide an air seal to the unit.
- Operating performance – Unit must be observed during operation to monitor proper performance of the unit and the vent system.
- Combustion gases – Flue products must be analyzed and compared to the unit specifications.
What do the -02 Integrated Control LED Codes indicate?
- LED Off: No power to control or control hardware fault detected
- Heartbeat: Control powered – displayed during all modes of operation if no errors are detected
- 1 Flash: Reverse line voltage polarity
- 2 Flashes: Improper earth ground
- 3 Flashes: Burner failed to light, or lost flame during heat demand
- 4 Flashes: Low flame signal – check flame sensor
- 5 Flashes: Watchguard – burner failed to light, exceeded maximum number of retries or recycles
- 6 Flashes: Not used
- 7 Flashes: Primary or Secondary limit open or watchguard mode – limit switch open longer than 3 minutes
- 8 Flashes: Rollout switch open
- 9 Flashes: Pressure switch failed to close or opened during heat demand
- 10 Flashes: Watchguard – Pressure switch opened 5 times during one heat demand
- 11 Flashes: Pressure switch stuck closed prior to activation of combustion air inducer
- 12 Flashes: Flame sensed without gas valve energized
- 13 Flashes: Low line voltage
What do the -03 Integrated Control LED Codes indicate?
- LED Off: No power to control or control hardware fault detected
- Heartbeat: Normal operation – idle, continuous fan, cool
- Continuous Rapid Flash: Call for heat / burner operation
- 1 Flash: Reverse line voltage polarity
- 2 Flashes: Improper earth ground
- 3 Flashes: Burner failed to light, or lost flame during heat demand
- 4 Flashes: Low flame signal – check flame sensor
- 5 Flashes: Watchguard – burner failed to light, exceeded maximum number of retries or recycles
- 6 Flashes: Not used
- 7 Flashes: Primary or Secondary limit open or watchguard mode – limit switch open longer than 3 minutes
- 8 Flashes: Rollout switch open
- 9 Flashes: Pressure switch failed to close or opened during heat demand
- 10 Flashes: Watchguard – Pressure switch opened 5 times during one heat demand
- 11 Flashes: Pressure switch stuck closed prior to activation of combustion air inducer
- 12 Flashes: Flame sensed without gas valve energized
- 13 Flashes: Low line voltage
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