Honeywell RTH6400 Series Quick Installation Manual page 25

Troubleshooting
Heating or
cooling system
does not
respond
"Cool On" or
"Heat On" is
flashing
Heat pump
issues cool air
in heat mode,
or warm air in
cool mode
• Press SYSTEM button to set system
to Heat. Make sure the temperature
is set higher than the Inside
temperature.
• Press SYSTEM button 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.
• Compressor protection feature is
engaged. Wait 5 minutes for the
system to restart safely, without
damage to the compressor.
• Check Function 2: Heat Pump
Changeover Valve to make sure
it is properly configured for your
system (see page 15).
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RTH6400
69-2210EF—03