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Oil Furnace - Won't Ignite

Article ID: 537
Last updated: 13 Mar, 2018

Oil Furnace

Re: Won't Ignite

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:
Bad Nozzle
Clogged Oil Filter
1 Electrodes Out of Adjustment
1 Bad Ignition Transformer
Bad Pump
2 Cracked Electrodes
Bad Primary Control
Stripped Pump Coupling
No Oil

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.
      • Still doesn't attempt to start = Bad Primary Control or Bad Cad Cell ⇒ Disconnect the Cad Cell wires and re-try.
  • 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 leaking seals at the oil filter.

2. Check Electrode Adjustment

  • Remove the nozzle assembly from the burner.

3. Check Ignition Transformer

  • Method 1: Transformer Tester
  • Method 2: Arc Test

4. Replace Nozzle

  • If the nozzle hasn't been replaced for the season, replace the oil nozzle.

5. 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.

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Article ID: 537
Last updated: 13 Mar, 2018
Revision: 4
Access: Public
Views: 173
Comments: 0