Greenheck DG / DGX Industrial Space Heating (464044 IOM) (Pre-2009) - Manual (Page 20)

Troubleshooting
24 Vac across
terminals W1 and X?
Summer/Off/Winter Switch set to Off or Summer
(Set to Winter)
Temp. sensor(s) TS or TS1 and TS2 Satisfied or Defective
(Reference direct gas start-up steps #8 and #9 to reset)
(Replace defective sensors)
Optional 7 Day Timer Incorrectly Set
(Set the 7 day timer. Reference the separate 7 day timer instructions
that shipped with the unit.) 115 Vac across
terminals 102 and 101?
Secondary Fuses (FU7) Blown
(Replace Fuses)
Main Transformer (TR1) Defective
(Replace Transformer TR1)
115 Vac across
terminals 105 and 101?
High/Low Gas Pressure Switch (PS1) Tripped
(Correct gas pressure and reset)
(Reference Direct Gas Start-Up Step #2 and 3)
115 Vac across
terminals 104 and 101?
High Limit (HLC1) Tripped
(Reset/Replace High Limit HLC1)
(Check on cause of control loss)
Continuity between
terminals 109 and 110?
Note: The power light on the flame safeguard should
blink approximately every 5 seconds as it
performs a self-diagnostics check.
115 Vac across
terminals 103 and 101?
Inlet Air Sensor (TS1) Holding
(Adjust TS1 setting -- Reference blower start-up step #6)
Heat Relay (R2) Defective
(Replace Heat Relay R2)
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Airflow Switch (PS2) Holding for Proper Airflow
(Correct airflow across burner)
(Reference Direct Gas Start-Up Step #4)
Yes
At this time the heater should attempt to light
(The pilot light on the flame safeguard should illuminate)
Heater Does Not Operate
Does not attempt to light (No visible spark)
T - 2