Natural Draft
Is an inducer found on a natural draft furnace?
no
Loaded thermocouple reading
10mv
If a furnace keeps tripping on limit, a common cause might be a
dirty filter
Why are natural draft furnaces no longer available?
inefficient
Disconnected thermocouple reading
20-30 mv
electric/electric unit
electric heat/ electric cooling package unit
How many pressure switches on a natural draft furnace?
0
Flame sensor reading
0.5-4.5 microamps
You hear a spark but furnace does not light, check for...
Cracked ceramic insulator
What kind of vent pipe is used for package units?
none
Does a thermopile light the burners?
no
What proves burner flame with an HSI?
flame sensor
A pressure switch proves what is working?
inducer
Besides an inducer, what else can be used to prove combustion airflow?
vane switch
A pilotless system uses...
HSI or Spark