Oil Furnace
Re: Starts/Burns Normally but Locks-Out
You arrive to find the flame safeguard control locked-out. You reset it and the burner ignites and burns properly, but after about 30 seconds it locks-out again.
Qty |
Possible Causes: |
1 |
Bad Cad Cell |
|
Bad Nozzle |
|
Clogged Oil Filter |
|
Bad Flame Safeguard |
|
Stripped Pump Coupling |
CHECKOUT:
1. Check Oil Flow
- Turn off power to the furnace.
- Remove the oil supply line from the nozzle assembly.
- Gently bend the supply line to be able to spray oil into a cup.
- Place a jumper across the thermostat input to the controller.
- Re-apply power to the furnace.
- If the burner does not start, press the reset button on the primary control to reset.
- Allow the furnace to pump oil for up to 5 seconds (stop by turning off power).
- Oil stream should start immediately with the pump motor.
- Oil stream should be continuous and have adequate pressure.
- Oil Pressure Inconsistent = Stripped Pump Coupling or Clogged Oil Filter ⇒ Check Pump Coupling and replace oil filter then recheck.
- Oil stream should be solid red (white foam indicates air).
- Air in Oil ⇒ Check for loose connections at the oil filter.
2. Test Ignition
- Re-connect the fuel line to the nozzle assembly.
- Initiate a call for heat.
- If the burner does not start, press the reset button on the primary control to reset.
- Ensure that the oil ignites without hesitation.
- Delayed Ignition = Bad Nozzle, Bad/Mis-Aligned Electrodes or Weak Ignition Transformer.
- After the burner starts, place a jumper across the Cad Cell wire terminals.
- Still Locks-Out = Bad Flame Safeguard
- Monitor the flame while the burner operates.
3. Check Cad Cell
- Disable the call for heat.
- Allow the furnace to shut-off and cool.
- Remove the Cad Cell eye from the burner.
- Use a Cad Cell tester to check the Cad Cell outside the furnace.
- Should show "Good" when exposed to a light source.
- Bad ⇒ Replace Cad Cell
- Good ⇒ Continue
- Re-install the Cad Cell eye.
- Use a Cad Cell tester to check the Cad Cell with the furnace operating.