STOELTING O231 (01) PDF DOCUMENT

The STOELTING O231 is a floor model, gravity-fed machine equipped with an IntelliTec2 control. It is designed to operate with almost any type of commercial soft serve or non-dairy mixes, including ice milk, ice cream, yogurt, and frozen dietary desserts.

Dimensional Specifications:

Width: 26 inches (66.0 cm)

Depth: 30 5/16 inches (77.0 cm)

Height: 62 1/2 inches (158.8 cm)

Detailed Specifications Table:

0231 Water Cooled			0231 Air Cooled
Dimensions	Machine	with crate	Machine	with crate
width	26″ (66,0 cm)	40-1/4″ (102,2 cm)	26″ (66,0 cm)	40-1/4″ (102,2 cm)
height	62-1/2″ (158,8 cm)	64-1/2″ (163,8 cm)	62-1/2″ (158,8 cm)	64-1/2″ (163,8 cm)
depth	31-1/2″ (80,0 cm)	33-1/4″ (84,5 cm)	31-1/2″ (80,0 cm)	33-1/4″ (84,5 cm)
Weight	640 lbs (290,2 kg)	730 lbs (331,1 kg)	640 lbs (290,2 kg)	730 lbs (331,1 kg)
Electrical	1 PH	3 PH	1 PH	3 PH
circuit ampacity (per barrel)	26A minimum	19A minimum	27A minimum	20A minimum
overcurrent protection device (per barrel)	40A maximum	30A maximum	40A maximum	30A maximum
Compressor	Freezing Cylinders – Two 14,000 Btu/hr (R-404A) Storage – 1,300 Btu/hr Compressor (R-134a)
Drive Motor	Two – 2 hp
Cooling	Water cooled units require 3/8″ N.P.T. water and drain fittings with 2 inlets and 2 outlets or 1/2″ N.P.T. water and drain fittings with 1 inlet and 1 outlet		Air cooled units require 3″ (7,6 cm) air space at back and sides.
Hopper Volume	Two – 6.5 gallon (24,7 liters)
Freezing Cylinder Volume	Two – 1 gallon (4 quart), 3,79 liters

Before operating or maintaining the STOELTING O231, it’s important to understand the following safety definitions:

Safety Alert Symbol: This symbol indicates danger, warning, or caution. Attention is required to avoid serious personal injury. The message that follows the symbol contains important information about safety.

Signal Words: Signal words are distinctive words used to alert the reader to the existence and relative degree of a hazard.

WARNING: The signal word “WARNING” indicates a potentially hazardous situation, which, if not avoided, may result in death or serious injury and equipment/property damage.

CAUTION (with safety alert symbol): The signal word “CAUTION” indicates a potentially hazardous situation, which, if not avoided, may result in minor or moderate injury and equipment/property damage.

CAUTION (without safety alert symbol): The signal word “CAUTION” not preceded by the safety alert symbol indicates a potentially hazardous situation, which, if not avoided, may result in equipment/property damage.

NOTICE: The signal word “NOTICE” indicates information or procedures that relate directly or indirectly to the safety of personnel or equipment/property.

Installation must be completed by a qualified electrician/refrigeration specialist. Incorrect installation may cause personal injury, severe damage to the machine, and will void the factory warranty.

1. Uncrate the machine.

2. Install the four casters. Turn the threaded end into the machine until no threads are showing. To level, turn out casters no more than 1/4″ maximum, then tighten all jam nuts.

3. The machine must be placed in a solid, level position. Accurate leveling is necessary for correct drainage of the freezing cylinder and to ensure correct overrun.

4. For STOELTING O231 models with air-cooled condensers, ensure a minimum of 3 inches (7.5 cm) of space on all sides and 10 inches (25 cm) at the top for proper circulation.

5. For STOELTING O231 models with a water-cooled condenser, they require 1/2″ NPT supply and drain fittings.

To install permanent wiring for the STOELTING O231, follow these steps:

1. Refer to the nameplate on the side panel of the machine for specific electrical requirements. Make sure the power source in the building matches the nameplate requirements.

2. Remove the back panel and the junction box cover located at the bottom of the machine.

3. Install permanent wiring according to local code.

To ensure safe operation of the STOELTING O231, please observe these rules:

A. Know the machine. Read and understand the Operating Instructions.

B. Notice all warning labels on the machine.

C. Wear proper clothing. Avoid loose-fitting garments, and remove watches, rings, or jewelry that could cause a serious accident.

D. Maintain a clean work area. Avoid accidents by cleaning up the area and keeping it clean.

E. Stay alert at all times. Know which switch, push button, or control you are about to use and what effect it is going to have.

F. Disconnect power for maintenance. Never attempt to repair or perform maintenance on the machine until the main electrical power has been disconnected.

G. Do not operate under unsafe operating conditions. Never operate the machine if unusual or excessive noise or vibration occurs.

Main Power On/Off: Supplies power to the IntelliTec2 control, freezing cylinder circuits, and storage refrigeration system. The control defaults to the On status with power to the hopper only when first plugged in. Pressing this button when the machine is on will turn it off.

Help: Displays help information dependent on the cursor’s location. Pressing it again exits the help screen.

Selection Button (SEL): Used to select menu options.

Set Button (SET): Used to save changes when modifying control settings.

On/Off Button (Left/Right): Controls power to the individual freezing cylinders.

Push to Freeze Button: Initiates “Serve Mode” for the respective cylinder.

Clean Button: Initiates “Clean Mode” for the respective cylinder.

Arrow Buttons (←, ↑, →, ↓): Used to navigate through control readings and settings.

Spigot Switch: Located behind the header panel, this switch is activated when a spigot is opened to dispense product, which begins “Serve Mode”.

Dispense Rate Adjustor: Located under the header panel to the right of the spigot handles. Turning the knob counterclockwise decreases the dispense rate.

Proper cleaning and sanitizing are crucial for food safety and machine maintenance. Here are the key points:

Important Differences:

Cleaning: Is the removal of soil materials (like milkfat and milkstone) from a surface. It is a prerequisite for effective sanitizing. An unclean surface will harbor bacteria that can defy sanitizing efforts.

Sanitizing: Kills bacteria but can only be effective on clean surfaces. Using a sanitizer on an unclean surface does not guarantee a clean and safe machine.

Proper Daily Maintenance:

1. CLEANING: Drain mix from the freezing cylinder, rinse with water, and then run a cleaner through the machine. Disassemble removable parts for sink cleaning.

2. MILKSTONE REMOVAL: Since most general-purpose cleaners do not remove milkstone (a white/gray film from dairy products), using a product like STERA-SHEEN or an equivalent daily is recommended. If high levels of milkstone have developed, a delimer may be necessary, but this should be done with caution as strong acids can damage machine parts.

3. SANITIZING: After cleaning and reassembly, run an FDA-approved sanitizing solution through the machine to kill bacteria before food preparation.

Important Notes:

• DO NOT USE BLEACH. Bleach has no cleaning properties and is corrosive, which will damage machine components.

• Use Chlorine Test Strips: Ensure your sanitizing solution maintains a concentration of 100 ppm active chlorine. Mix new solutions if the concentration falls below this level.

Follow these steps to disassemble the machine parts. Inspect parts for wear (like the wear line on auger flights) and replace if necessary. Frequency of cleaning must comply with local health regulations.

A. Disassembly of Front Door:

1. Turn the machine off by pressing the Main Power Off/On button on the IntelliTec2 control.

2. Remove the knobs on the front door.

3. Remove the front door by pulling it off the studs.

4. Remove the spigot through the bottom of the front door.

5. Remove all o-rings from parts. First, wipe off lubrication with a clean towel. Then, squeeze the o-ring upward to form a loop and roll the o-ring out of its groove.

B. Disassembly of Auger:

1. Remove the front auger support and bushing.

2. Remove the auger assembly from the machine barrel slowly. As the auger is being pulled out, carefully remove each of the plastic flights with springs.

3. Keep the rear of the auger tipped up once it is clear of the freezing cylinder to prevent the rear seal assembly from dropping.

4. Wipe the spline lubricant off the hex end of the auger with a paper towel. Remove the rear seal assembly.

5. Unscrew the springs from the auger flights.

Local and state health codes will dictate the specific procedure required. The following is a general guideline.

Cleaning Disassembled Parts:

A. Prepare detergent water by mixing 2 oz. of Palmolive detergent or equivalent in 2 gallons of 90° to 110°F (32° to 43°C) water. Place all parts in the detergent solution and clean with the provided brushes.

B. Rinse all parts with clean 90° to 110°F (32° to 43°C) water.

Cleaning the Machine Interior:

C. Wash the hopper and freezing cylinder with the 90° to 110°F (32° to 43°C) detergent water and brushes provided.

D. Clean the rear seal surfaces from the inside of the freezing cylinder with the 90° to 110°F (32° to 43°C) detergent water.

Sanitizing Machine Parts:

1. Use Stera-Sheen or an equivalent sanitizing solution mixed to a 100 parts per million strength. Mix in quantities of no less than 2 gallons of 90° to 110°F (32°C to 43°C) water.

2. Place all parts in the sanitizing solution for 5 minutes, then remove and let them air dry completely before assembling.

Assembling the Machine:

NOTICE: Petrol-Gel sanitary lubricant or equivalent must be used. Lubricants used on food processing equipment must be certified for this use.

A. Assemble all o-rings onto parts dry, without lubrication. Then apply a thin film of sanitary lubricant to the exposed surfaces of the o-rings.

B. Lubricate the rear seal area on the auger shaft with a thin layer of sanitary lubricant. Install the rear seal o-ring. Lubricate the outside of the rear seal o-ring with sanitary lubricant.

C. Lubricate the inside metal surface of the rear seal and install it onto the auger shaft. DO NOT lubricate the outside of the rear auger seal.

D. Lubricate the hex drive end of the auger with a small amount of spline lubricant.

E. Screw the springs onto the studs in the plastic flights completely to provide proper compression.

F. Install the two plastic flights onto the rear of the auger and insert it part way into the freezing cylinder.

G. Install the remaining plastic flights, push the auger into the freezing cylinder, and rotate it slowly until it engages the drive shaft.

H. Apply a thin layer of sanitary lubricant to the inside and outside of the auger support bushing. Install the bushing onto the auger support and install the auger support into the front of the auger. Rotate the auger support so that one leg of the support points straight up.

I. Apply a thin layer of sanitary lubricant to the o-rings on the spigot body and install the spigot body through the bottom of the front door.

K. Apply a thin film of sanitary lubricant to the door seal o-ring and fit it into the groove on the rear of the front door.

M. Place the front door assembly on the mounting studs and push the front door against the machine carefully.

N. Secure the front door by placing the knobs on the studs and tightening until finger-tight. Do not overtighten. A proper o-ring seal can be observed through the transparent front door.

Sanitizing must be done after the machine is clean and just before it’s filled with mix.

A. Prepare 2 gallons of sanitizing solution (100 ppm strength) following the manufacturer’s instructions.

B. Install the mix inlet regulator into the hopper.

C. Pour the sanitizing solution into the hopper.

D. Make sure the display shows the freezing cylinder is off. If the freezing cylinder is not off, the control will not go into Clean mode.

E. Press the CLEAN button.

F. Check for leaks at the front door seals and the drain tray.

G. Using a sanitized soft bristle brush, clean the hopper sides, mix inlet regulator, and underside of the hopper cover with the sanitizing solution.

H. After five minutes, open the spigot to expel the sanitizing solution. Drain all of the solution from the machine.

I. When the solution has drained, press the CLEAN button to stop the auger. Allow the freezing cylinder to drain completely.

The machine is now sanitized and ready for adding mix.

A. Sanitize the machine immediately before use.

B. Make sure the display shows the freezing cylinder is off. If not, press the corresponding On/Off button to turn it off.

C. Fill the hopper with at least 2.5 gallons of mix.

D. Place a container under the spigot and open it to allow the mix to flush out about 8 ounces (0.23 liters) of sanitizing solution and liquid mix.

E. Press the On/Off button for the cylinder.

F. Press the PUSH TO FREEZE button. (Note: There is a 3-second delay before the compressor starts).

G. When the product is at 75% consistency, the display will read “SERVE”. Open the spigot to dispense product.

H. The machine dispenses product at a reasonable draw rate. If the machine is overdrawn, resulting in a soft product, allow it to run for approximately 30 seconds before dispensing more. The dispense rate can be adjusted with the knob under the header panel.

I. Do not operate the machine when the MIX LOW message is displayed. Refill the mix container immediately.

Product Consistency Adjustment: If the product consistency needs to be adjusted, you will need the Technician passcode to access the Basic Settings menu. Adjust the ‘CutOut Consistency’ setting higher to increase firmness or lower to decrease it. Make adjustments in increments of 5 for best results.

The control readings and settings are accessed by using a keypad sequence. From the Current Status screen, press the left arrow button to access the passcode input screen. The available options depend on the access level.

Associate Level: Press the right arrow, then the SEL button. (Limited access).

Manager Level: Press the right arrow, then the up arrow, then the SEL button. (Access to Associate options plus performance, error, and statistics screens).

Technician Level: Press the right arrow, then the SET button, then the SEL button. (Full access to all control options).

Updating the firmware on the IntelliTec2 is simple. You will need a USB flash drive.

1. Download the .rom file onto the top level of the USB drive (do not put the file in a folder).

2. Unplug the machine from electrical power.

3. Remove the header panel and locate the USB connector on the display module.

4. Connect the USB flash drive to the display module.

5. Connect power to the machine.

6. The display should show “Restoring Factory Defaults” in a large font, and a progress bar will be shown at the bottom. If this text does not appear, ensure the .rom file is in the top level of the USB flash drive and not inside any folders.

A. Remove the back panel.

B. Use a Burroughs Belt Tension Gauge to set the tension for the drive belt. The belt tension should be set to 45-55 lbs.

C. If an adjustment is necessary, loosen the four motor plate retaining nuts (tension adjustment nut), adjust the belt tension, then retighten the four nuts.

D. Using a straightedge, check that the drive motor pulley is aligned with the speed reducer pulley. Align the pulley if necessary.

NOTE: Belt life will be increased if new drive belts are tightened after two or three weeks of operation.

The STOELTING O231 has two condensers that require periodic cleaning to maintain refrigeration efficiency. If the condenser is not kept clean, efficiency will be lost.

For Air-Cooled Condensers:

A. Visually inspect the condenser for dirt.

B. If the condenser is dirty, place a wet towel over the condenser.

C. Using compressed air or a CO2 tank, blow out the dirt from the back of the condenser. Most of the dirt will cling to the wet towel.

D. An alternative method is to clean with a condenser brush and vacuum.

For Water-Cooled Condensers:

These are a tube and shell type. They require a cool, clean supply of water to properly cool the machine. Inlet and discharge lines must be 3/8″ I.D. minimum.

It is recommended that a preventative maintenance schedule be followed to keep the machine clean and operating properly.

A. Daily Checks:

Check for any unusual noise or condition and repair immediately.

B. Monthly Checks:

Check the condenser for dirt and clean if necessary.

C. Quarterly Checks:

Check drive belts for wear and tighten belts if necessary.

Follow these steps for storing the machine over any long period of shutdown time:

A. Clean all parts that come in contact with mix thoroughly with a warm detergent water. Rinse in clear water and dry all parts. Do not sanitize. Do not let cleaning solution stand in the freezing cylinder or hopper during the shutdown period.

B. Remove, disassemble, and clean the front door and auger shaft. Leave these parts disassembled during the shutdown period.

C. Place the auger flights and auger support bushing in a plastic bag with a moist paper towel. This will prevent them from becoming brittle if exposed to dry air for over 30 days.

D. For water-cooled machines left in unheated buildings subject to freezing, the water must be shut off and disconnected. Disconnect the water inlet fitting at the rear of the machine. Run the compressor for 2-3 minutes to open the water valve (the front door must be attached). Blow out all water through the water inlet and drain the supply line. Disconnect the water outlet fitting.

E. Press the Main Power On/Off button to turn the machine off.

F. Disconnect the machine from the source of electrical supply.

When the STOELTING O231 experiences a problem, an error code will be displayed. To return to normal operation, the condition must be corrected and the power to the affected freezing cylinder must be cycled off and on using the On/Off button.

Error Code 2 – High Torque (E2): The drive motor is running at a high load for 10+ seconds. This may be due to the product consistency being set too high. Turn the cylinder off, wait for the product to thaw, then turn it back on. Reduce the product consistency. If the error persists, contact your Authorized Stoelting Distributor.

Error Code 3 – Run Time (E3): The compressor has run continuously for an extended period. This is usually caused by low mix levels or a restriction preventing mix from entering the freezing cylinder (like ice crystals). Check mix levels and for blockages. For air-cooled units, check for restricted airflow. If the error persists, contact your Authorized Stoelting Distributor.

Error Code 4 – Clean (E4): The machine has been in “Clean Mode” for more than 20 minutes. This is a safeguard and not a machine problem. To clear, press the On/Off button for the cylinder to turn it off, then back on.

Error Code 5 – Freezing Cylinder Sensor (E5): Indicates a failure of the barrel sensor or it’s out of range. Press the On/Off button to cycle power. The machine will continue to run on preset timers to allow service to be scheduled. If the error persists, contact your Authorized Stoelting Distributor.

Error Code 6 – Hopper Sensor (E6): This error will not occur on the STOELTING O231 model.

Error Code 7 – Drive Motor (E7): The control does not sense current from the drive motor. Press the On/Off button to cycle power. If the error persists, contact your Authorized Stoelting Distributor.

Error Code 8 – Cab Sensor (E8): This error will not occur on the machine.

Error Code 9 – High Pressure Cutout (E9): Usually caused by a dirty or inefficient condenser. On an air-cooled machine, check for proper air clearance. On a water-cooled machine, check for proper water flow and for kinks in hoses. If the error persists, contact your Authorized Stoelting Distributor.

Error Code 10 – Auxiliary Sensor (R10): Occurs if the temperature sensor on the control board fails. Press the On/Off button to cycle power. If the error persists, contact your Authorized Stoelting Distributor.

Error Code 11 – Prime Error (E11): This error will not occur on the machine.

Error Code 12 – Left Hopper Sensor (E12): Indicates a failure of the left hopper sensor or it’s out of range. Press the On/Off button to cycle power. If the error persists, contact your Authorized Stoelting Distributor.

Error Code 13 – Right Hopper Sensor (E13): Indicates a failure of the right hopper sensor or it’s out of range. Press the On/Off button to cycle power. If the error persists, contact your Authorized Stoelting Distributor.

Problem	Possible Cause	Remedy
Machine does not run.	1. Power to machine is off.	1. Supply power to machine.
	2. Freeze-up (auger will not turn).	2. Turn Clean/Off/On switch Off for 15 minutes, then restart.
	3. Front door not in place.	3. Assemble front door in place.
Machine will not shut off.	1. Drive belt failure.	1. Replace drive belt.
	2. Consistency temperature setting is too firm.	2. Turn Consistency Adjustment knob counter-clockwise.
	3. Refrigeration problem.	3. Check system. (Call distributor for service).
Product is too firm.	1. CutOut Consistency setting too high.	1. Adjust the CutOut Consistency (See Section 3).
Product is too soft.	1. No vent space for free flow of cooling air.	1. A minimum of 3″ of air space at the back. (See Section 2).
	2. Condenser is dirty.	2. Clean the condenser. (See Section 3).
	3. CutOut Consistency setting too low.	3. Adjust the CutOut Consistency (See Section 3).
	4. Auger is assembled incorrectly.	4. Remove mix, clean, reassemble, sanitize and freeze down.
	5. Refrigeration problem.	5. Check system. (Call distributor for service).
Product does not dispense.	1. No mix in hopper.	1. Add mix to the hopper.
	2. Drive motor overload tripped.	2. Wait for automatic reset. (If condition continues, call distributor for service.)
	3. Drive belt failure.	3. Replace drive belt.
	4. Freeze-up (Auger will not turn).	4. Turn off cylinder, wait for 15 minutes, then restart.
Drive belt slipping or squealing.	1. Worn drive belt.	1. Replace drive belt.
	2. Freeze-up (Auger will not turn).	2. Turn off cylinder, wait for 15 minutes, then restart.
	3. Not tensioned properly.	3. Adjust belt tension.
Rear auger seal leaks.	1. Outside surface of rear auger seal is lubricated.	1. Clean lubricant from outside of rear seal, lubricate inside of seal and reinstall.
	2. Rear seal missing or damaged.	2. Check or replace.
	3. Seal o-ring missing, damaged or installed incorrectly.	3. Check or replace.
	4. Worn or scratched auger shaft.	4. Replace auger shaft.
Front door leaks.	1. Front door knobs are loose.	1. Tighten knobs.
	2. Spigot parts are not lubricated.	2. See Section 3.
	3. Chipped or worn spigot o-rings.	3. Replace o-rings.
	4. O-rings or spigot installed wrong.	4. Remove spigot and check o-ring.
	5. Inner spigot hole in front door nicked or scratched.	5. Replace front door.

Part	Description	Quantity
208135	Brush – 4″ X 8″ X 16″ (Barrel)	1
208380	Brush – 1/4″ X 3″ X 14″	1
208401	Brush – 1″ X 3″ X 10″	1
208467	Brush – 3/8″ X 1″ X 5″	1
236059	Card – Cleaning Instruction	1
324103	Decal – Caution Rotating Shaft	1
324105	Decal – Caution Electrical Shock	1
324106	Decal – Caution Electrical Wiring Materials	1
324107	Decal – Caution Hazardous Moving Parts	1
324125	Decal – Danger Electric Shock Hazard	1
324141	Decal – Caution Rotating Blades	1
324200	Decal – High Pressure Cut-Out	1
324208	Decal – Attention Refrigerant Leak Check	1
324509	Decal – Cleaning Instructions	1
324548	Decal – Adequate Ventilation 6″	1
324566	Decal – Wired According To	1
324594	Decal – Attention Heat Sensitive	4
324686	Decal – Danger Automatic Start	1
324728	Decal – Contactor Identification	1
324803	Decal – Domed Stoelting Logo (Large) (Header Panel)	1
324888	Decal – Fan Motor Reset	1
324896	Decal – Contactor Identification	1
324901	Decal – Transformer Switch	1
368448	Filter – Air (Condenser)	1
508048	Lubricant – Spline (2 oz Squeeze Tube)	1
508135	Petrol Gel – 4 oz Tube	1

Part	Description	Quantity
149003	Bushing – Front Auger Support	2
232734	Cap – Rosette – Teardrop	3
314477	Cover – Hopper	2
381804	Auger Flight	10
417006	Grid – Drip Tray (Metal)	1
482019	Knob – Front Door (Black)	4
624598-5	O-Ring – Outside Spigot – Black (5 Pack)	4
624614-5	O-Ring – Top & Bottom Center Spigot – Black (5 Pack)	2
624664-5	O-Ring – Middle Center Spigot – Black (5 Pack)	1
624677-5	O-Ring – Mix Inlet – Black (5 Pack)	4
624678-5	O-Ring – Rear Seal – Black (5 Pack)	2
625133	O-Ring – Front Door – Red	2
666786	Seal – Rear Auger – Black	2
694255	Spring – Auger Flight	5
744273	Tray – Drip	1
744252	Tray – Drain (Black Plastic)	1
2147799	Mix Inlet Assembly – 3/16″ Hole – Extended Length (2LA)	2
2177072	Extension – Spigot – 1.5″	–
2177073	Extension – Spigot – 2.5″	–
2177074	Extension – Spigot – 3.2″	–
2177428	Door w/Pins	1
2187811	Spigot Body – Center	1
2187812	Spigot Body – Outer	2
3170644	Support – Front Auger	2
3156795	Auger Shaft	2