AG2 Troubleshooting Flow Chart
8
Is the power at the heater
120V?
Check power across the
green and white wires of the
yellow control cord. Is the
power 24V?
Is the power across the 24V
terminal on the circuit board
and ground on the circuit
board 24V?
Find the source of the electrical
problem between panel & heater.
YES
YES
NO
Is the power across the TH
terminal on the circuit board
and ground on the circuit
board 24V?
YES
Is the inlet or the outlet of the unit
obstructed? I.e. ice, birds nest, dirt, etc.
Remove obstruction.
YES
Check for loose wiring or restrictions in hose
connections to the pressure switch. Are they
ok?
NO
Repair wiring or hose
connections.
NO
After 30 minutes of non-operation has
passed, is there a flash code for ASP-1 or
ASP-2 failure (2 or 3 flashes)?
YES
Replace the switch after verifying the
following:
* Baffle(s) is in the tube(s) farthest
from the burner.
* Heater, fan blower, squirrel cage,
intake and exhaust are clean and free
from dirt and obstructions.
* The 4” air intake pipe does not
exceed 20 feet and/or 2 elbows.
* There is not a negative pressure
experienced at the area of air intake
(i.e. attic space, high-winds, very tight
building).
YES
During the first 45 seconds of power
up, is there 120 Volts going to the
ignitor?
NO
Replace ignitor.
YES
Turn up thermostat
NO
YES
NO
Is there 120V on the primary side
of the external transformer?
NO
Find the source of the electrical
problem between panel &
external transformer.
NO
Is there 120V on the primary
side of the internal transformer?
NO
Transformer is faulty and
must be replaced.
The internal
transformer is faulty
and must be replaced.
NO
The relay board is
faulty and must be
replaced.
Does the fan
blower turn on?
NO
Is the circuit board
sending 120V to
the fan?
Does the ignitor warm
up and glow red?
Is the ignitor
physically damaged?
NO
Replace ignitor.
YES
NO
Check voltage at ignitor during the
ignition sequence (usually 30-45 seconds
after power to heater). Is it 120V?
NO
Is the resistance through
the ignitor45-400 ohms?
YES
YES
YES
Is there 24V on the secondary
side of the external transformer?
Is there 24V to the
thermostat?
YES
The circuit board is faulty
and must be replaced.
NO
YES
NO
Find source of electrical
problem between transformer
and thermostat.
YES
The thermostat or wiring is
faulty and should be replaced
or repaired.
The circuit board is
faulty and must be
replaced.
Remove obstruction.
YES
NO
Is the fan obstructed?
NO
YES
The Fan is faulty and
must be replaced.
Replace circuit board.
NO
Is there a fault
flash code? See
page 7 for chart.
NO YES
YES
Replace faulty wiring.
YES
