Troubleshooting - Honeywell RTH5100B Quick Installation Manual

Advanced Installation Guide

Troubleshooting

If you have difficulty with your thermostat, please try the following sugges-
tions. Most problems can be corrected quickly and easily.
Display is blank
Temperature
settings do not
change
Cannot change
system setting to
Cool
Fan does not turn
on when heat is
required
69-2329EF—03
• Make sure fresh AAA alkaline batteries are
correctly installed (see page 7).
• 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).
• Check Function 1: System Type to make sure it is
set to match your heating and cooling equipment
(see page 13).
• Check Function 3: Heating Fan Control to make
sure it is set to match your heating equipment (see
page 15).
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