UHA LOW PROFILE UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL
SECTION 13: TROUBLESHOOTING 13.1 General
START
Are gas & electrical | No | Turn on supplies. | |
supplies on? | |||
|
|
WARNING
Explosion Hazard
Installation, service and annual inspection must be done by a contractor qualified in the installation and service of
Turn off gas and electrical supplies before performing service or maintenance.
Failure to follow these instructions can result in death, injury or property damage.
Yes
Is ignition control showing a
"4 flashes" LED code?
Noo
Is ignition control showing a
"2 flashes" LED code?
No
Does the flue
blower run?
| UHA 30 - 75: Press in reset | |
| button on manual reset limit | |
| switch. UHA 100 - 125: Wait | |
Yes | 10 - 15 minutes for limit Yes | |
| switch to cool. Does fan | |
| stop running? | |
| No | |
| Replace temperature | |
| limit switch. | |
| Burner has locked out due | |
Yes | to ignition failure. Use | |
Troubleshooting for | ||
| ||
| Automatic Ignition Burner | |
| Systems section to test | |
| burner. | |
No | Use Troubleshooting for | |
Flue Blower section to test | ||
| fan. |
Fan and limit switch are operating normally.
Yess
With external controls (i.e. |
| Has burner “Locked Out”? No | |
thermostat) on, does the No | |||
burner continue through the |
|
| |
heating cycle? |
|
| |
|
| Yes | |
|
| Use Troubleshooting for | |
|
| Automatic Ignition Burner | |
|
| Systems section to test burner. | |
Yes |
|
| |
Heater Operating |
| If problems persist, contact | |
No | |||
TROUBLESHOOT ENDS. | |||
| |||
The limit switch has |
|
tripped. See Manual Reset No | Replace limit switch. |
Limit Switch Figure. |
|
Yes
Ensure proper air flow clearance for axial fan. Open louvers slightly.
Replace axial fan if it does
not operate.
38