NOMA THM501 (01) PDF DOCUMENT

The NOMA THM501 programmable thermostat includes the following features:

• Extra-large LCD display with backlight that sets and displays house temperature (°C or °F), day, hour, and minute (in 12- or 24-hour format).

• Temperature can be set in half-degree increments.

• Interfaces with a humidifier for automatic humidity control.

• Interfaces with heating/air conditioning systems for automatic temperature control.

• Automatic change-over for HEATING/COOLING programs.

• Ability to copy one day’s program to another day.

• Automatic ventilation feature.

• Selectable cycle rate.

• Usage monitor to track system run time.

• Filter change reminder.

• Millivolt & 24 V compatibility.

• Includes mounting hardware and 2 “AA” batteries.

When you first install the batteries in your NOMA THM501, it is recommended to perform a hard reset to set the thermostat to its default settings. This is also how you select your preferred temperature scale (°C or °F) as a one-time setup step.

1. First, press and hold the LOCK key.

2. While holding down the LOCK key, press and release the RESET (R) key located above the battery compartment on the back of the thermostat. The LCD screen will go blank momentarily.

3. Once the display reappears, release the LOCK key.

4. The temperature display will immediately appear and flash. During this time, you can select Fahrenheit (°F) by pressing the UP or DOWN key. If you do nothing, the display will stop flashing and the default Celsius (°C) scale will be selected.

Please note: The temperature scale (°C or °F) cannot be changed afterwards unless you perform another hard reset, which will clear all programs and settings.

To set the clock and calendar on your NOMA THM501, follow these steps:

1. Press the SET CLOCK button to start. The time and the SET symbol will begin to flash.

2. Use the AHEAD or BACK buttons to set the current time.

3. Press the SET CLOCK button again. The day and the SET symbol will now flash.

4. Use the AHEAD or BACK buttons to set the current day of the week.

5. Press SET CLOCK to exit. If you are in HEAT mode, you may need to press SET CLOCK twice to exit, as the first press after setting the day will enter the Humidifier Control function.

The NOMA THM501 comes with a pre-programmed 7-day schedule for your convenience, with four periods per day (P1-P4). You can use this schedule or set your own custom programs.

P1: MORNING: Typically for when you wake up and may prefer a warmer temperature.

P2: DAY: An energy-saving mode for when you are away from home.

P3: EVENING: For when you return home and want a comfortable temperature.

P4: NIGHT: A sleep mode for energy savings or comfort.

The default schedule is as follows:

To set a custom heating schedule on your NOMA THM501, follow these steps:

1. Press the MODE button until the HEAT symbol appears on the display.

2. Press the PROGRAM button once. The P1 and SET PROGRAM symbols will appear.

3. Select the day you want to program (MON, TUE, WED, etc.) by pressing the WEEKDAY button.

4. Use the AHEAD or BACK buttons to select the desired start time for the P1 (Morning) period. Program times can be set in 10-minute increments.

5. Use the UP or DOWN buttons to set the desired temperature for P1. The temperature can be set in increments of 0.5°.

6. After setting the time and temperature for P1, press PROGRAM again to display P2 (Day). Repeat steps 4 and 5 to set the time and temperature for P2.

7. Press PROGRAM again to display P3 (Evening). Repeat the steps for P3 and again for P4 (Night).

8. To program another day of the week, press WEEKDAY to select the next day and repeat the entire process.

To exit programming at any time, press the HOME button. Note that the program times you set here will also be used for the cooling program.

To program the cooling schedule on your NOMA THM501:

1. Press the MODE button until the COOL symbol appears on the display.

2. Repeat the same programming procedure as you did for the heating program. Press PROGRAM to enter programming mode, WEEKDAY to select the day, AHEAD/BACK to set the time, and UP/DOWN to set the desired cooling temperature.

Note: The program start times are shared between heating and cooling. Any changes made to the times in cooling mode will also affect the times in heating mode. The setpoint temperature range for cooling is 8°C to 35°C (48°F to 95°F).

You can press and hold the AHEAD/BACK or UP/DOWN keys to change the numbers more quickly. To exit programming, press HOME.

The Copy Program function allows you to copy a full day’s program settings (both HEAT and COOL) to another day. This is useful after you have programmed one day completely.

1. Make sure the thermostat is in the program setting mode by pressing PROGRAM. The SET PROGRAM symbol will appear.

2. Use the WEEKDAY button to select the day you wish to copy FROM.

3. Once the source day is selected, press the COPY button. The COPY symbol will appear on the display.

4. The following day of the week will start flashing, indicating it is the destination day. If you want to copy to this day, press COPY again.

5. If you wish to copy to a different day, use the WEEKDAY button to select the desired destination day, then press COPY.

6. The program settings from the first day will be copied to the selected day. Repeat these steps for any other days you wish to copy the program to.

To temporarily change the temperature without altering your program, simply press the UP or DOWN button to set your desired temperature. The OVERRIDE symbol will appear on the display. This new temperature setting will be maintained until the next scheduled program time, at which point the thermostat will automatically return to its regular program.

The HOLD function on the NOMA THM501 allows you to maintain a constant temperature indefinitely, disabling all scheduled programs until the HOLD is canceled.

• To activate HOLD: Press the HOLD button once. Then, use the UP or DOWN buttons to set the desired hold temperature. The HOLD symbol will appear on the display to indicate the function is active.

• To cancel HOLD: Press the HOLD button again. The HOLD symbol will disappear, and the thermostat will return to the currently scheduled program.

To prevent accidental changes to your settings, you can use the Key Lock function on your NOMA THM501 thermostat.

• To lock the keypad: Press and hold the LOCK button for 3 seconds. The lock symbol will appear on the display.

• To unlock the keypad: Press and hold the LOCK button for 3 seconds again. The lock symbol will disappear.

The current active program (e.g., P1, P2, P3, or P4) is always displayed on the lower right-hand section of the LCD screen. To review all other program settings for the week, press the PROGRAM button at any time to scroll through and check each setting. To return to the normal display, press the HOME button.

The humidifier control feature on the NOMA THM501 only works if a humidifier is properly connected to the thermostat’s H1 and H2 terminals, and it only functions when the thermostat is in HEAT mode.

To set the humidity level:

1. Ensure the thermostat is in HEAT mode.

2. Press the SET CLOCK button three times to enter the humidity setting mode. The SET HUMIDITY symbol will appear, and the humidity level setting will flash.

3. Use the UP or DOWN buttons to set the desired humidity level in increments of 5%. The range is from 20% to 70%.

4. To turn the humidifier OFF, press DOWN until “OFF” appears.

5. Press SET CLOCK to exit.

The humidifier will turn on whenever the relative humidity in the room is lower than the set humidity level. When the humidifier is on, a water drop symbol will appear on the display.

The Temperature Trend Graph is displayed in the upper left section of the LCD screen on your NOMA THM501. It shows the trend of temperature changes over time. You read the graph from right to left, with the rightmost bar representing the most recent temperature reading.

The graph can be displayed in two scales:

• 1 Hour (Total 8 Hour): Each bar represents a 1-hour interval, showing the temperature trend over the past 8 hours.

• 3 Hour (Total 24 Hour): Each bar represents a 3-hour interval, showing the trend over the past 24 hours.

To change the scale, press the USAGE button, then press UP or DOWN to toggle between the 8-hour and 24-hour views.

The NOMA THM501 is equipped with a ‘Pre-comfort Recovery’ system. This feature intelligently activates the heating or cooling system in advance of a scheduled program time (up to one hour earlier) to ensure the room reaches the desired temperature right at the start of that program period. When the system is in ‘recovery’ mode, the OVERRIDE symbol will flash on the display. This feature can be disabled in the “Optional Settings” menu if desired.

The Usage Monitor on the NOMA THM501 tracks the total run time of your heating and cooling equipment (the system “ON” time).

• Press the USAGE button once to view USAGE TODAY. This value automatically resets to zero every day at midnight.

• Press the USAGE button again to view USAGE THIS WEEK. This value automatically resets at the end of the week (00:00:00, with a new week beginning on Monday morning).

The NOMA THM501 thermostat tracks the total system “ON” time (for HEAT, COOL, or FAN). When this time accumulates to approximately 500 hours, the FILTER CHANGE indicator will appear on the LCD screen, reminding you that it’s time to change your system’s filter.

To reset the counter after changing the filter, press and hold the USAGE button for 3 seconds until the FILTER CHANGE symbol appears momentarily. This resets the counter back to zero.

You can control your system’s fan using the FAN button on the NOMA THM501. Press the button to cycle through the following modes:

• AUTO: In cooling mode, the fan starts and stops with the cooling equipment. In heating mode, the fan is controlled by the heating equipment itself and usually starts a few minutes after the heat turns on.

• ON: The fan runs continuously, regardless of whether the heating or cooling system is active.

• VENT (Automatic Ventilation): The thermostat will turn the fan on periodically to improve air circulation and ventilation, even when heating or cooling is not required.

When the fan is running, the fan symbol on the display will be animated.

Press the MODE button on your NOMA THM501 to toggle between the different system operating modes:

• HEAT: Controls the heating system only.

• COOL: Controls the cooling system only.

• AUTO: Allows for automatic change-over between heating and cooling. The thermostat will automatically decide whether to turn on the heat or the air conditioning based on the ambient room temperature.

• OFF: Both the heating and cooling systems will be turned off. All programs and settings are disabled in this mode.

When the heating system is running, the heat symbol will animate. When the cooling system is running, the cool symbol will animate.

To customize advanced features on your NOMA THM501, press the OPTION button to enter the optional settings menu. Press OPTION repeatedly to cycle through the settings, and use UP/DOWN to change the value for each setting. Press HOME at any time to exit.

The available settings are:

1. 12/24 Hour Display Format: Choose between 12hr or 24hr clock format.

2. Heat Cycle Rate (Cr-0 to Cr-4): Select the cycle rate that matches your heating equipment to prevent rapid cycling. The factory default is Cr-3.

3. HE/HG Setting: Selects fan operation for your heating system. HE is for electric heating systems (fan turns on immediately). HG (default) is for gas or oil-fired furnaces (fan is controlled by the furnace).

4. Backlighting (ON/OFF): Choose BL-1 for ON or BL-0 for OFF. When enabled (BL-1), the backlight only comes on in the dark and stays on for 8 seconds after a key press.

5. Pre-comfort Recovery (ON/OFF): Choose RE-1 for ON (default) or RE-0 for OFF.

6. LCD Contrast Selection (CO-0 to CO-9): Adjust the screen contrast if it appears too dim or dark. CO-0 is the lowest contrast, and CO-9 is the highest. The factory default is CO-6.

When the battery symbol flashes on the LCD screen, the batteries are low and need to be replaced. It is recommended to replace the batteries once a year even if the indicator is not flashing.

1. Press the MODE button until the thermostat is in the OFF mode.

2. Carefully remove the thermostat’s main body from its mounting plate (the back cover that is fixed to the wall).

3. Remove the old batteries from the compartment on the back.

4. Install 2 new “AA” size batteries quickly, following the polarity markings.

5. Replace the thermostat onto its mounting plate.

Note: If you insert the new batteries within 20 seconds of removing the old ones, the clock setting will not be lost. Otherwise, you will need to set the time and day again. The programs and thermostat settings are stored in permanent memory and will not be lost.

The NOMA THM501 thermostat has two types of resets:

• SOFT RESET: This is used if the thermostat shows an abnormal display. Press the RESET (R) key located on the back of the thermostat above the battery compartment. A soft reset will restart the thermostat but will keep all your programmed schedules and settings stored in memory. You will only need to set the clock again.

• HARD RESET: This is used to clear the permanent memory, including all stored programs and thermostat settings, or to change the temperature scale between °C and °F. To perform a hard reset, press and hold the LOCK key. While holding it, press and release the RESET (R) key on the back. When the display reappears, release the LOCK key. The thermostat will be set back to its original default settings.

Number of programs: 7 Day with 4 settings per day

Temperature display range: 0 – 55°C (34 – 99.5°F)

Humidity display range: 20 to 95%

Temperature setting range: 5 – 35°C (41 – 95°F)

Humidity setting range: 20 to 70%

Storage temperature range: -20 – 50°C (-4 – 122°F)

Battery: 2 x “AA” size batteries

If the LCD screen on your NOMA THM501 is blank, please try the following solutions:

1. Check if the batteries are installed correctly, paying attention to the polarity.

2. Ensure the batteries are fresh and of the correct type (alkaline is recommended).

3. Press the RESET (R) key located on the back of the thermostat, above the battery compartment.

If the heat is not turning on with your NOMA THM501, please check the following:

1. Ensure the thermostat is set to the HEAT or AUTO mode.

2. Check that the set temperature is higher than the current room temperature displayed on the screen.

3. The thermostat has a built-in time delay of up to 5 minutes to prevent undesirable on/off sequences. You may need to wait for this delay to pass before the heat turns on.

4. After waiting, the heating should engage. The heat symbol will be animated on the display whenever the heating system is running.

If the NOMA THM501 indicates that the heat is on (animated symbol) but you are not getting warm air, follow these steps:

1. Check if the furnace switch and/or pilot flame is on, as it may have been turned off.

2. Allow several minutes for the heating system to heat up and for the fan to activate. Most heating systems have a delay before the fan starts blowing warm air.

3. Check that the HE/HG setting in the optional settings menu is set correctly for your type of heating system (Refer to Optional Settings).

4. If the heat still does not come on, re-check the wiring installation.

If your air conditioning will not turn on, check these points:

1. Ensure the NOMA THM501 is set to the COOL or AUTO mode.

2. Verify that the set temperature is lower than the current room temperature.

3. The thermostat has a built-in time delay (up to 5 minutes) to protect the air conditioner compressor. You may need to wait for this period to pass.

4. After the delay, the AC should turn on. The cool symbol will animate on the display when the cooling system is running.

If the display shows the cooling system is active but it is not working, try these steps:

1. Check if the air conditioning system’s main power switch or circuit breaker is turned on.

2. Wait several minutes for the system to activate. If it still does not turn on, check the thermostat’s wiring installation.

This is normal operation if the Pre-comfort Recovery system is enabled on your NOMA THM501. This feature activates the heating or cooling system in advance of the scheduled time to ensure the room reaches the desired temperature at the start of the program. If you prefer the system to turn on exactly at the programmed time, you can disable this feature in the optional settings menu.

If your heating system is cycling too frequently, it is likely that the selected Heat Cycle Rate does not match your heating equipment. You can adjust this in the optional settings. The default is Cr-3 for gas or oil forced air systems. Try selecting a slower cycle rate (a lower Cr number) or disable the cycling (Cr-0). When disabled, the thermostat will operate at a fixed span of ±0.5°C (±1.0°F) around the setpoint.

The NOMA THM501 has a built-in safeguard time delay of 30 minutes to prevent undesirable and rapid change-over sequences between heating and cooling. For example, if the cooling system was just running, the thermostat will wait at least 30 minutes before it can switch to heating mode. This is normal operation. You can manually override this delay by pressing the MODE button to select either HEAT or COOL directly.

This happens when you set the HEAT and COOL program temperatures very close to one another. To prevent overlapping or conflicting temperature settings, the NOMA THM501 automatically maintains a minimum separation of 3°C (6°F) between the two. The COOL temperature setting will always be forced to be at least 3°C (6°F) higher than the HEAT temperature setting. For example, if you raise the HEAT program temperature to 24°C, and the COOL temperature was set at 24°C, the thermostat will automatically push the COOL temperature up to 27°C to maintain the separation and prevent overlap.

Selecting the temperature scale (°C or °F) on the NOMA THM501 is a one-time start-up process. After the initial battery installation and hard reset, you CANNOT change the temperature scale unless you perform another HARD RESET. A hard reset will clear all your stored programs and thermostat settings, returning the unit to its factory defaults.

To perform a hard reset and select the scale:

1. Press and hold the LOCK key.

2. While holding the LOCK key, press and release the RESET (R) key on the back of the unit.

3. Release the LOCK key when the display reappears.

4. While the temperature display is flashing, quickly press UP or DOWN to select °F. To select °C, do not press any buttons and wait for the display to stop flashing.