Roberts Gorden UHD[X][S][R] 125 User Manual

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SECTION 13: T
ROUBLESHOOTING
31
SECTION 13: TROUBLESHOOTING
13.1 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 Figure.
No
Use Troubleshooting for
Automatic Ignition Burner
Systems section to test burner.
Has burner “Locked Out”?
Yes
No
With external controls (i.e. 
thermostat) on, does the 
burner continue through the 
heating cycle?
No
Yes
Does the flue blower run?
No
Use Troubleshooting for 
Flue Blower section to test 
fan.
Yes
Yes
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?
Yes
No
Yes
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?
Yes
No
Yes
Turn on supplies.
Are gas & electrical
supplies on?
No 
Yes
START
WARNING
Explosion Hazard
Installation, service and annual inspection 
must be done by a contractor qualified in 
the installation and service of gas-fired 
heating equipment or your gas supplier.
Turn off gas and electrical supplies before 
performing service or maintenance.
Failure to follow these instructions can 
result in death, injury or property damage.