Honeywell RTH8500 Owner's Manual

19
Troubleshooting
If you have difficulty with your thermostat, please try the following suggestions.
Most problems can be corrected quickly and easily.
Display is blank • Check circuit breaker and reset if necessary.
• Make sure power switch at heating & cooling system is on.
• Make sure furnace door is closed securely.
• Make sure fresh AAA alkaline batteries are correctly installed.
Temperature
settings do not
change
Make sure heating and cooling temperatures are set to acceptable
ranges:
• Heat: 40° to 90 °F (4.5° to 32 °C).
• Cool: 50° to 99 °F (10° to 37 °C).
Heating or
cooling system
does not respond
• Press SYSTEM to set system to Heat. Make sure the temperature
is set higher than the Inside temperature.
• Press SYSTEM to set system to Cool. Make sure the temperature
is set lower than the Inside temperature.
• Check circuit breaker and reset if necessary.
• Make sure power switch at heating & cooling system is on.
• Make sure furnace door is closed securely.
• Wait 5 minutes for the system to respond.
Cannot change
system setting
to Cool
• Check Function 0170: System Type to make sure it is set to
match your heating and cooling equipment.
Fan does not
turn on when
heat is required
• Check Function 0180: Heating Fan Control to make sure it is set
to match your heating equipment.
Heating system
is running in cool
mode
• Check Function 0170: System Type to make sure it is set to
match your heating and cooling equipment.
Red light is on • If thermostat is in Emergency Heat mode the red light is normal.
It shows that the thermostat is in emergency heat mode.
• If thermostat is not in Emergency Heat mode, contact a qualified
service contractor for repair.
“Wait” appears
on the screen
• Compressor protection feature is engaged. Wait 5 minutes for the
system to restart safely, without damage to the compressor.
Heat pump
issues cool air
in heat mode, or
warm air in cool
mode
• Check Function 0190: Heat Pump Changeover Valve to make
sure it is properly configured for your system.
For assistance with this product, please visit http://yourhome.honeywell.com or
call Honeywell Customer Care toll-free at 1-800-468-1502.

Honeywell RTH8500 Specifications

General

Hold Feature	Yes
Compatibility	Works with most heating and cooling systems
Temperature Range	40°F to 90°F
Weight	250 g
Programmable	7-day programmable
Dimensions	4.5 x 3.5 x 0.9 inches (114 x 89 x 23 mm)