Honeywell T8611G installation instructions Troubleshooting Guide Symptom Possible Cause Action

T8611G CHRONOTHERM® IV DELUXE PROGRAMMABLE HEAT PUMP THERMOSTATS

TROUBLESHOOTING GUIDE

Table 6. Troubleshooting Guide.

Symptom	Possible Cause		Action
Display will not	Thermostat is not being	•	Check for 24 Vac between R and C terminals.
come on.	powered.		— If missing 24 Vac:
			— check if the circuit breaker is tripped—reset the circuit
			breaker.
			— check if the system fuse is blown—replace the fuse.
			— check if the power switch on the HVAC equipment is in
			the Off position—set to the On position.
			— check wiring between thermostat and HVAC
			equipment—replace any broken wires and tighten any
			loose connections.
			— If 24 Vac is present, proceed with troubleshooting
Temperature	Room temperature display has	Enter Installer Setup number 37 and reconfigure the display.
display is incorrect.	been reconfigured.
	Thermostat is configured for °F	Enter Installer Setup number 14 and reconfigure the display.
	or °C display.
	Bad thermostat location.	Relocate the thermostat.
Temperature	The upper or lower temperature	Check the temperature setpoints:
settings will not	limits were reached.	•	Heating limits are 40 to 90°F (4.5 to 32°C)
change. (Example:		•	Cooling limits are 48 to 99°F (7 to 37°C)
Cannot set the
	The setpoint temperature range	Check Installer Setup numbers 34 and 35 and reconfigure the
heating higher or
	stops were configured.	setpoint stops.
the cooling lower.)
Heating will not	No power to the thermostat.	•	Check for 24 Vac between R and C terminals.
come on.			— If missing 24 Vac:
			— check if the circuit breaker is tripped—reset the circuit
			breaker.
			— check if the system fuse is blown—replace the fuse.
			— check if the power switch on the HVAC equipment is in
			the Off position—set to the On position.
			— check wiring between thermostat and HVAC
			equipment—replace any broken wires and tighten any
			loose connections.
			— If 24 Vac is present, proceed with troubleshooting.
	Thermostat minimum off time is	Wait up to five minutes for the system to respond.
	activated.
	System selection is not set to	Set system selection to Heat.
	Heat.
	Heating setpoint is below room	Check heating setpoint. Set heating setpoint to desired
	temperature.	temperature.
Cooling will not	No power to the thermostat.	•	Check for 24 Vac between R and C.
come on.			— If missing 24 Vac:
			— check if the circuit breaker is tripped—reset the circuit
			breaker.
			— check if the system fuse is blown—replace the fuse.
			— check if the power switch on the HVAC equipment is in
			the Off position—set to the On position.
			— check wiring between thermostat and HVAC
			equipment—replace any broken wires and tighten any
			loose connections.
			— If 24 Vac is present, proceed with troubleshooting.
	Thermostat minimum off time is	•	Wait up to five minutes for the system to respond.
	activated.	•	Enter Installer Setup number 33. Reconfigure minimum off
			time (if required).
	System selection is not set to	Set system selection to Cool.
	Cool.
	Cool setpoint is above room	Check cooling setpoint. Set cooling setpoint to desired
	temperature.	temperature.

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