Greenheck DG / DGX Industrial Space Heating (464044 IOM) (Pre-2009) - Manual (Page 21)

Troubleshooting
No
Check for proper pilot pressure.
(Direct Gas Start-Up #2)
Check inlet gas pressure.
(Direct Gas Start-Up Step #1) Note: The minimum and maximum gas pressures for your unit are
shown on the direct gas label.
Reference direct gas start-up procedure #1
Gas pressure between the min
and max shown on the direct gas
label? Correct gas pressure
(Reference Direct Gas Start-Up Step #1)
Proper spark?
Crossed flame and spark wires
(Uncross wires and reconnect)
Incorrect spark plug gap
(Set spark plug gap to 0.062 in.)
Defective spark plug
(Replace spark plug)
Pressure drop across the burner
between 0.625 and 0.675 in. wc?
Adjust burner baffles
(Reference Direct Gas Start-Up Step #4)
Air in the gas line?
Purge gas line
(Verify gas at the pilot)
No
No
Yes
No
No
Yes
Yes
Yes
No
Note: A high pilot pressure will make lighting more difficult. Lower the
pilot pressure in increments until the unit lights. Then set the pilot per
the instruction in Direct Gas Start-Up procedure #2)
Yes
Adjust the pilot pressure
(Reference Direct Gas Start-Up Step #2)
Heater Does Not Operate
Attempts to light but no visible pilot (Visible spark)
Pilot pressure correct?
Yes
With proper airflow, gas pressure and spark,
the unit should light.
If problems remain, consult the factory
T - 3