Thermo Pride GMC-85 Installation And Service Manual page 37

All installations and services must be performed by qualified service personnel.
Yes
Does system run until
thermostat is satisfied?
Yes
Does burner shut off
when thermostat is
satisfied?
Yes
Does the circulating air
blower turn off after
thermostat is satisfied
within 4 minutes?
Yes
Troubleshooting Complete.
No Has the high limit thermostat
or auxiliary high limit
thermostat activated?
Check for reduced airflow through
the furnace. This may be caused
by an excessively restrictive duct
system, an inadequate amount of
supply air,especially for furnaces
installed in closets, or extremely
dirty air filters. Also, check and
confirm heat input rate to unit is
within specifications.
No Check for short in wire
to thermostat. Replace
thermostat, if necessary.
Check fan timer settings
against those on connection
No
diagram. Is fan selector
switch set on "manual".
Reset if necessary. Does
fan still fail to turn off?
No
Yes
Yes
36
Check all wiring for
loose connections.
Replace fan timer.