What does “1 COM”, “2 COM”, or “3 COM” mean on my Honeywell Thermostat?
If “1 COM”, “2 COM”, or “3 COM” is displayed on your Honeywell Thermostat, the thermostat is not communicating correctly with the W8835 or W8635A,B. Check the connection to terminal 1 at the thermostat and W8835 or W8635 EIM: replace any broken wires and cycle power.
What to do if my Honeywell Thermostat heating does not come on?
If the heating isn't working, first, make sure the setpoint is higher than the room temperature. Second, check that the System selection is set to Heat. Finally, if the heating setpoint is indeed below room temperature, allow five minutes for the system to respond, during which the thermostat will display “Wait”.
What to do if my Honeywell T8635L Thermostat cooling does not come on?
If the cooling isn't working, first, make sure the setpoint is below the room temperature. Second, check that the System selection is set to Cool. Finally, if the cooling setpoint is above room temperature, allow five minutes for the system to respond, during which the thermostat will display “Wait”.
How to fix a Honeywell T8635L when the display does not come on?
If the Honeywell Thermostat display doesn't come on, the issue is likely a power problem. First, ensure the thermostat is correctly mounted and latched on the wallplate. Then, check the circuit breaker and reset it if it has tripped. Next, verify the fuse in the fuse box and replace it if blown. Also, check that the power switch at the equipment is in the On position. Finally, inspect the wires on terminals 2 and 3 for 24 VAC; replace any broken wires. If power is present, the thermostat may need replacement.
What does 'wait' mean on my Honeywell T8635L Thermostat, and why isn't cooling or heating starting?
If “wait” is displayed and the call for Cool (or Heat when used in a heat pump application) has not started on your Honeywell Thermostat, compressor protection is likely active. This feature can be set from 0 to 5 minutes to prevent compressor damage from rapid cycling. Wait until the compressor protection period expires. To bypass this during installation, refer to the Installer System Test section.
Why does my Honeywell T8635L system switch only display “off only”?
If the system switch setting displays “off only” on your Honeywell Thermostat, it is likely that during Automatic Discovery mode, the thermostat did not correctly set the number of heat or cool stages. Run Automatic Discovery mode by cycling power to the equipment. You can also manually run Discovery mode in Installer Setup, or manually configure heat and/or cool stages (Installer Setups 5, 8 and 9).
Why isn't the 2nd stage heat or cool working on my Honeywell T8635L Thermostat?
If the 2nd stage heat or cool does not energize on your Honeywell Thermostat (only when used with W8635A), the stage configuration might not be correctly set, or the cool load at the W8635 EIM is not connected correctly. Set the Stage configuration in Installer Setup for two stages of heat and/or two stages of cool. Check that 24 Vac is present at Y2, W2 or Aux. Terminal, depending on the EIM used. If 24 Vac is not present, all connections are good and the thermostat is properly configured, replace W8635A EIM or W8835.
Why doesn't the emergency heat work on my Honeywell T8635L?
If the Emergency Heat does not energize on your Honeywell Thermostat (only when used with W8635B or W8835), the Emergency Heat load at W8635 or W8835 may not be connected correctly. Check that 24 Vac is present at the E terminal. If 24 Vac is not present, all connections are good, and the thermostat is properly configured, replace W8635B or W8835.
What does “Filter” mean on Honeywell T8635L Thermostat?
The “Filter” display along with the green LED indicates that the filter has expired. No answer.
Why is the red LED lit on my Honeywell T8635L Thermostat?
The red LED indicates that the heat pump has signaled the thermostat about a problem. If you have a multistage heat pump, move the System switch to the Em.Ht setting. See Heat Pump Operating Instructions or no answer.
General| Power Source | Battery or Hardwired |
|---|---|
| Programmable | Yes |
| Power Method | Battery or Hardwired |
| Mounting | Wall Mounted |
| Color | White |
| Display | Digital |
| Temperature Differential | 1°F |
| Control Type | Digital |
Details the physical keys on the thermostat cover and next to the display.
Explains the information shown on the thermostat display screen.
Details how Adaptive Intelligent Recovery™ optimizes comfort and saves energy.
Instructions for setting the heating/cooling system and fan modes.
How to select Heat, Off, Cool, or Auto system modes.
How to set the fan to Auto or On operation.
How to temporarily adjust temperature settings.
Temporarily override current schedule until next period.
How to set a permanent temperature hold.
Setting a temporary hold for a specific duration like vacation.
How to view the outdoor temperature if sensor is equipped.
How to check current temperature setpoints and modes.
How to set or reset the filter change reminder.
Indicates when temperature is overridden remotely.
How to set the current day and time on the thermostat.
How to adjust the thermostat for Daylight Saving Time.
Overview of 7-day programming and its four periods.
Details the default preprogrammed schedule for all days.
Table for planning and customizing a custom 7-day schedule.
Steps to begin programming the thermostat's schedule for a day.
Troubleshooting problems with the thermostat display not showing information.
Resolving issues where temperature settings do not change or heating/cooling fails.
Diagnosing problems with system indicators, no air from registers, or filter alerts.
Addressing 'no com' errors, zoning delays, and early heat/cool activation.
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