White-Rodgers FAQ

1. How does a digital thermostat determine when to bring on second stage?
   Digital thermostats constantly monitor the performance of 1st stage. When the system is within 1 degree of set point for an extended period (good system performance) the second stage will take longer to come on even if you increase the set point. If you are more than 1 degree from set point the calculation in the thermostat starts counting down until it brings the second stage on. With second stage the system usually satisfies for heat or cool and turns off. On the next cycle the second stage will come on sooner because the memory in the thermostat remembers it's previous performance. Most models have a way to bring second stage on quickly to test second stage. This can also be used to bring on the second stage quickly whenever a customer wants.
2. Is there a quick test to help determine if a digital thermostat is operating correctly?
   A quick test to determine if a digital thermostat is working properly is to use the following diagnostic: Set System Switch to HEAT and raise the set point above the room temperature by a few degrees. Within a few seconds (up to five minutes on Heat Pump Models) the thermostat should make a soft click sound. This sound usually indicates the thermostat is operating properly. If the thermostat does not click, try the reset operation listed in the instructions. If the thermostat does not click after being reset contact your distributor or place of purchase for a replacement. If the thermostat clicks but the system does not come on you can bypass the thermostat briefly to test the system. Cool: The diagnostic for Cooling is the same as heating diagnostic (above) except to test cooling set the System to COOL and lower the set point below room temperature. There may be up to a five minute delay before the thermostat clicks in Cooling.
3. Where can my customer call for help programming their thermostat?
   For assistance programming call 1-800-284-2925. For faster service they should have the Model or Type Number of the thermostat ready. A copy of the programming instructions will also help them follow along with the technician's instructions.
4. Can a single stage thermostat be used on a multi-stage system?
   A single stage thermostat sends only one signal for heating and one signal for the compressor and fan. If the multi-stage system requires two signals a dedicated multi-stage thermostat would be required. Some new multi-stage systems work correctly with a single stage thermostat because they have a control module that controls the staging. The manufacturer of the appliance can quickly determine if your system is designed to operate with a single stage thermostat.
5. What is the function of an "O" or "B" terminal on a White-Rodgers digital thermostat?
   The "O" terminal is energized constantly when the thermostat is in the cool position. The "B" terminal is energized constantly in the heat position. These terminals are typically used for controlling heat pump equipment or on systems with dampers.
6. How long does a thermostat typically last?
   The normal product design criteria is 15 years. Operation at higher than rated voltages or current, even briefly, can cause an electronic circuit to open and require a replacement control. For warranty information on products contact your installer or distributor.
7. The thermostat backlight no longer lights up, can the light be replaced?
   Indicator or backlights are not replaceable on thermostats. If the thermostat has a backlight option in the configuration menu verify it is turned on. If the thermostat uses batteries, replace the batteries and/or clean the battery contacts inside the back of the thermostat. Use a pencil eraser to gently polish each of the battery contacts. Do not bend them up and down or they may break. When complete they should be as shiny as a mirror. If this does not correct the condition a replacement thermostat would be indicated.
8. What do Aux, Emer, and Malf mean on a heat pump thermostat?
   Aux or Auxiliary Heat is the second stage of heat in the Heat mode. This is energized when the Heat Pump is not keeping up with the thermostat setting. It is normal operation with most heat pumps for the thermostat to call for auxiliary heat. If the auxiliary heat and emergency heat are using the same back-up heat source the thermostat may also show an Emergency Heat indication whenever the Auxiliary heat is on. Emer or Emergency Heat occurs when the thermostat is switched to Emergency. The thermostat bypasses the Heat Pump and uses the back-up heat. This is useful if the pump is not operating correctly or if the temperature outside is so cold that the pump is not economical to run. If the Auxiliary Heat and Emergency Heat are using the same back-up heat source the thermostat may show the Auxiliary and Emergency Heat indication at the same time. Malf or Malfunction indicates the heat pump system is sending a signal to the malfunction terminal on the thermostat marked "L". It does not indicate a malfunction in the thermostat. The manufacturer of the Heat Pump system can determine the likely cause of a malfunction signal being sent to the thermostat. Note: Occasionally some heat pump systems will trickle a small amount of voltage to "L" when there is no system malfunction.
9. Do you repair or rebuild thermostats or heating and cooling controls?
   We do not repair or rebuild any thermostats or controls. If a thermostat or control does not operate properly a replacement would be indicated. Replacement information can be located on our website.
10. Can I change the temperature display on a thermostat to match the old thermostat?
    In normal use the temperature display on a digital thermostat reads very accurately. If however, a heating or cooling system is oversized or undersized or the location of the thermostat is not ideal it can cause the temperature display for the room to read high or low. The current 70's, 80's and 90's do offer an adjustable temperature display to allow you to match your old thermostat reading. This adjustment option is located in the Configuration Menu section of the thermostat installation instructions.
11. What happens if a battery fails on a battery powered thermostat?
    White-Rodgers thermostats feature an exclusive, patented, low battery indicator. The patented low battery indicator will offset the temperature 10 degrees from set point when the thermostat senses that the battery only has approximately 1 month of life left. This offset will call the homeowners attention to the thermostat and the homeowner will see "batt" flashing very large in the display making it clear that the batteries need to be changed. This is an exclusive White-Rodgers feature making White-Rodgers the brand least likely to experience a complete battery power failure event. Most current production models also include a built-in mechanical device that will cycle the heat on and off at approximately 40 degrees.
12. My thermostat (with a remote sensor) display shows 08 degrees or the room temperature is steadily dropping. How do I troubleshoot the system?
    Comfort-Set II (Older Models)
    Single Stage Models: Verify jumper wire W-22 on the back of the thermostat (not the subbase) has been clipped. Multistage and Heat-Pump Models: Verify jumper wire W-18 on the back of the thermostat (not the subbase) has been clipped.
13. Comfort-Set III/Comfort-Set 90/ 90 Series (Current Models)
    Single Stage Models: Verify jumper wire W-922 on the back of the thermostat (not the subbase), has been clipped and the ends separated. You must also enable the remote sensor option in the Installation Instructions, Configuration Menu. Multistage and Heat Pump Models: When installing a remote sensor you must enable the remote sensor option in the Installation Instructions, Installer Menu.
    
    Troubleshooting Chart
    To function correctly and read temperature accurately, the thermostat (when set up for a remote as outlined above) must have constant 24-volt power. If the thermostat temperature is steadily dropping, reading low, or reads 08° when a remote sensor is installed, it can be traced to one of the three following conditions.

Note: Digital thermostats and remote sensors acclimate very slowly to temperature change. It may take an hour or more for the temperature to acclimate to the room temperature from a low temperature reading as outlined above. To expedite the room temperature display use the reset instructions listed in the installation instructions for the thermostat model you are working with. When reset, the thermostat will default to a room temperature of 70° and begin sensing room temperature. Be sure to reconfigure the installer menu for a remote sense or because the reset function may cancel remote sensing.

14. When an Electronic Air Cleaner snaps or arcs what should I look for?
    Typically arcing subsides in a few hours unless there are large particles in the air stream. If the condition persists after a day or so you may want to test the cells individually. On an air cleaner with 2 collecting cells remove the cells and cut a 2"X4" board the length of one cell. Insert the 2"X4" into the cabinet first using it as a spacer. Insert one cell at a time and test the operation of the air cleaner with the blower on. If one cell arc's constantly and one does not you can visually inspect the two cells side by side. Compare them top to bottom, left to right looking for bent plates, cracked or broken insulators, broken Ionizing wires or a foreign object shorting across the cell. Also inspect the pre-filter for frayed wire that could short to the collecting cells. If nothing is detected visually wash the collecting cells one more time using the washing outlined in the instructions. If the condition persists a replacement cell would be indicated.
15. Should I recommend washing an Electronic Air Cleaner collecting cell in the dishwasher?
    Some Electronic Air Cleaner manufacturers may recommend washing cells in an automatic dishwasher. We prefer the method outlined in the Owner's Manual because: Some automatic dishwashers have rotating parts (internally) that may damage or bend the collecting cell. The fingers on the interior dishwasher rack do not always accommodate the cell and may bend the cell plates.
    Some drying agents used in automatic dishwashers may cause a film to build up on the cells and reduce cleaning efficiency. The dirt and material removed by air cleaners can be very small and may stain some plastic dishwasher interiors.
16. On a Hot Surface Ignition (HSI) system what can cause intermittent operation?
    Items that can cause intermittent operation or nuisance lockouts on an HSI system are: Carbon deposits on the flame probe which can be cleaned with emery cloth, a poorly grounded furnace, reversed polarity on the primary or secondary of the transformer. You can obtain specific instructions for wholesale HSI models from our Website. For original equipment models troubleshooting instructions may be available from the heater manufacturer.