CALL FOR HIGH FIRE WITH TWO-STAGE THERMOSTAT
I 2 StageThermostat
YES NO
Combustion Air Inducer ON I
I
(100% Rate Speed)
_ NO---_
YES
Adjust Indoor
B}ower to
Appropiate speed
1
Wait for Catl for Heat Satisfied
Increase Combustior
Air Inducer Speed
if Not at 100%
Rate Speed
System will always light at 70% even if 2nd stage call for heat is in place
,_ If the high pressure switch does not close within 5 attempts, the system
will operate at low fire for the remainder of the call for heat at request
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