TROUBLESHOOTING
Call for heat,
Thermostat contacts close
Does the LED
stay OFF?
NO
Does it give
1 Flash?
NO
Does it give
3 Flashes?
NO
Does it give
5 Flashes?
NO
After Pre-purge
Does Valve operate and
sparks start?
YES
Does it give
2 Flashes?
NO
Does
system run until call for
heat ends?
YES
Normal Operation
YES
If correct voltage present: Unit has internal fault - replace.
- Unit is seeing a flame signal with valve closed
YES
Check for partial shorting on flame probe wiring
There is a fault in the internal safety relay drive
YES
There is an internal fault with the Main Valve relay
YES
Check wiring to Valve if it does not operate
NO
Check spark wiring for shorts if no sparks
Check sparks are at burner, not to outer casing
Ensure no breaks or cracks in insulation of spark lead
Ensure pilot flame reaches flame sensor for detection
Burner has failed to light after permitted attempts
YES
Check limit switches, Check sensor leads, Check ground continuity
NO
Check gas jets are clear, Check for clean burn
Check low voltage to module (TH-TR).
If no voltage: Check Limit Switches
Check flame probe and wiring
Check for poor burner ground wiring
- Check supply voltage is within spec.
If it is - replace control
Check for short between TH and MV
If no external cause - replace control
- replace Valve if voltage present
Check gas supply and pressure to valve
Check sparks and wiring as above
Check flame remains on flame sensor
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