Honeywell RTH6400 Series - Troubleshooting

Advanced Installation Guide
69-2210EF—03 22
Troubleshooting
SETUPWIRINGASSISTANCETROUBLESHOOTING
Troubleshooting
If you have difficulty with your thermostat, please try
the following suggestions.
Most problems can be corrected quickly and easily.
Display is blank • MakesurefreshAAalkaline
batteries are correctly installed
(see page 7).
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).
Cannot change
system setting
to Cool
• CheckFunction 1: System Type to
make sure it is set to match your
heating and cooling equipment
(see page 14).
Fan does
not turn on
when heat is
required
• CheckFunction 3: Heating Fan
Control to make sure it is set to
match your heating equipment (see
page 16).