RTH6400
27 69-2584ES—01
Troubleshooting
SETUP WIRING ASSISTANCE TROUBLESHOOTING
Heating or
cooling system
does not
respond
• 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.
“Cool On” or
“Heat On” is
flashing
• 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 2: Heat Pump
Changeover Valve to make sure
it is properly configured for your
system (see page 14).
Heating system
is running in
cool mode
• CheckFunction 1: System Type to
make sure it is set to match your
heating and cooling equipment
(see page 13).