Honeywell MagicStat 28 Programming And Installation Instructions page 34

The furnace cycles too frequently,
or the system cycle length
is too short or too long.
The thermostat current
setting does not match the
display temperature to within
Incorrect room temperature
showing on thermostat display.
Readjust system on-time according to instructions on
pages 16 and 17.
Check that the wiring hole in the wall behind the
wallplate has been plugged with insulation to
± °
1 . prevent drafts that might adversely affect
thermostat operation.
Be aware that it is normal for the current setting
and display temperature to differ on occasion.
During recovery from setback or setup, setting and
display temperatures may differ for up to 30 minutes
after recovery period.
Make sure hole behind thermostat is plugged with
insulation to help prevent drafts from adversely
affecting thermostat operation.
The thermostat is factory-calibrated, and cannot be
adjusted.
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