NOTICE
Bypassing any switch is intended for testing purposes only. Do not leave switch bypassed
during normal operation or the heater’s built-in safety mechanisms will be compromised.
Is there 120V on the primary side
of the external transformer?
Is there 24V on the secondary side
of the external transformer?
Is there 24V to the
thermostat?
15
4.0
Troubleshooting Guide
Key
Start
Question
Process
Question
Corrective
Action
AG2
Series
No
Find the source of the electrical
problem between panel and the
external transformer.
No
The transformer is faulty
and must be replaced.
Yes
No
Find source of electrical
problem between
the transformer and
thermostat.
Yes
The thermostat wiring
is faulty and should be
replace or repaired.
Yes
