User manual

SECTION 14: TROUBLESHOOTING
35 of 47
14.1 General
Ensure air flow through the
heat exchanger is
appropriate per the rating
plate.
If problems persist, contact
Roberts-Gordon LLC at
www.rg-inc.com
Heater Operating
TROUBLESHOOT ENDS.
No
Replace limit switch.
The limit switch has
tripped. See Manual Reset
Limit Switch section.
No
Use Troubleshooting for
Automatic Ignition Burner
Systems section to test burner.
Has burner “Locked Out”?
Ye s
No
With external controls (i.e.
thermostat) on, does the
burner continue through the
heating cycle?
No
Ye s
Does the flue blower run?
No
Use Troubleshooting for
Flue Blower section to test
fan.
Ye s
Ye s
Burner has locked out due
to ignition failure. Use
Troubleshooting for Automatic
Ignition Burner Systems
section to test burner.
Is ignition control showing a
"2 flashes" LED code?
Ye s
No
Ye s
Fan and limit switch are
operating normally.
Replace temperature limit
switch.
UHD 75: Press in reset
button on manual reset limit
switch. UHD 100 - 125: Wait
10 - 15 minutes for limit
switch to cool. Does fan
stop running?
No
Is ignition control showing a
"4 flashes" LED code?
Ye s
No
Ye s
Turn on supplies.
Are gas & electrical
supplies on?
No
Ye s
START