Honeywell chronotherm t8602c Manuale Utente

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T8602C CHRONOTHERM
® 
IV DELUXE PROGRAMMABLE THERMOSTATS
11
69-1670
TROUBLESHOOTING GUIDE
Table 6. Troubleshooting Guide.
Symptom
Possible Cause
Action
Display does not 
come on.
Thermostat is not being 
powered.
• Check if batteries are present and installed correctly.
— If batteries are present and installed correctly, replace 
thermostat.
Temperature 
display is incorrect.
Room temperature display has 
been reconfigured.
Enter Installer Setup number 37 and reconfigure the display.
Thermostat is configured for °F 
or °C display.
Enter Installer Setup number 14 and reconfigure the display.
Bad thermostat location.
Relocate the thermostat.
Temperature 
settings do not 
change. (Example: 
Cannot set the 
heating higher or 
the cooling lower.)
The upper or lower temperature 
limits were reached. 
Check the temperature setpoints:
• Heating limits are 40 to 90°F (4.5 to 32°C)
• Cooling limits are 48 to 99°F (7 to 37°C)
The setpoint temperature range 
stops were configured.
Check Installer Setup numbers 34 and 35 and reconfigure the 
setpoint stops.
Heating does not 
come on.
No power to the thermostat.
• Check for 24 Vac between R and W terminals (check for 
750 mV on PowerPile
®
 Systems).
— 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 
activated.
Wait up to five minutes for the system to respond.
System selection is not set to 
Heat.
Set system selection to Heat.
Heating setpoint is below room 
temperature.
Check heating setpoint. Set heating setpoint to desired 
temperature.
Cooling does not 
come on.
No power to the thermostat.
• Check for 24 Vac between R or RC and Y terminals 
— 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 
activated.
• Wait up to five minutes for the system to respond.
• Enter Installer Setup number 33. Reconfigure minimum off 
time (if required).
System selection is not set to 
Cool.
Set system selection to Cool.
Cool setpoint is above room 
temperature.
Check cooling setpoint. Set cooling setpoint to desired 
temperature.