Hired-Hand Universal Ray Tube Heaters: AG2 Series Rev.10-08 - Manual (Page 17)

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.
17
4.0 Troubleshooting Guide
AG2 Series
Measure the voltage across
the red wire on the relay
board and ground on the
circuit board. Is there 24V?
If the heater does not enter High Fire mode, check the following:
Check the power across the green
and black wires of the yellow
control cord. Is there 24V?
Yes
Repair or replace the faulty
wiring or thermostat.
Yes
The valve is
faulty and must
be replaced.
The high fire relay is faulty
and must be replaced.
No
No
NOTE: To confirm that the heater is not in high fire
mode, check the manifold pressure. If it is 3.5” (natural
gas) or 10” (propane), the indicator light is faulty and
should be replaced. If approximately 2.0” to 2.5”
(natural gas) or 5.0” to 6.5” (propane), the heater is in
low fire mode and the troubleshooting steps described
here should be followed.
Check to make sure gas pressure is within minimum and
maximum inputs, as indicated on the heater’s rating plate.
Is gas pressure OK?
Were the gas lines purged of air?
Is the heater properly
grounded? Is the heater’s
polarity correct?
With microampmeter, check DC
amperage at flame rod. Is it
greater than 1.0 microamps?
Check to make sure flame
sensor wire is OK and then
replace circuit.
Sensing rod is faulty or flame is weak.
Check to make sure heater is operating
at proper gas pressure as indicated on the
heater’s rating plate and then, if needed,
replace sensing rod.
Replace gas valve. Yes
Correct problem.
Correct problem.
No
No
Yes Yes
No
Yes
Purge gas line.
No