Honeywell T8600D Owner's Manual - Page 18

DELUXE PROGRAMMABLE THERMOSTAT TROUBLESHOOTING GUIDE Symptom Action Display will not come on. • Check if the thermostat is mounted and latched on the wallplate-mount and latch the thermostat on the wallplate. • Check if the circuit breaker is tripped-reset the circuit breaker. • Check if the fuse is blown-replace the fuse. • Check if the system switch at the equipment is in the Off position-set to On position. • Check wiring between thermostat and HVAC equipment- replace any broken wires. • If 24 Vac is present, proceed with troubleshooting. Temperature settings will not change (Example: cannot set the heating higher or the cooling lower). • Check that the temperature setpoints are: - heating: 40 to 90°F (7 to 31°C) - cooling: 45 to 99°F (9 to 37°C). "Filter" flashing in display. • Indicates a filter timer needs to be reset. - See Viewing and Resetting Timer Settings instructions. Heating will not come • Check that setpoint is above room temperature. on. • Check if the circuit breaker is tripped-reset the circuit breaker. • Check if the fuse is blown-replace the fuse. • Check if the system switch at the equipment is in the Off position-set to On position. • If 24 Vac is present, proceed with troubleshooting. • Wait five minutes for the system to respond. • Set system selection to Heat. Cooling will not come on. • Check that setpoint is below room temperature. • Check if the circuit breaker is tripped-reset the circuit breaker. • Check if the fuse is blown-replace the fuse. • Check if the system switch at the equipment is in the Off position-set to On position. • If 24 Vac is present, proceed with troubleshooting. • Wait five minutes for the system to respond. • Set system selection to Cool. System on indicator Wait a minute after seeing the flame or snowflake and then (flame=heat, check the registers. snowflake=cool) is lit, but no warm or cool air is coming from the registers. 69-1400-1 18