Safety first: Turn off power and gas. If you smell gas, ventilate the area and do not attempt to light the boiler.

Step 1 – Verify gas supply: Confirm that the manual gas shutoff is open and other gas appliances work.
Step 2 – Check spark location: Ensure the spark electrode is positioned where gas exits the burner. Adjust according to the manufacturer’s dimensions.
Step 3 – Inspect burner orifice: Remove the burner and check the orifice for debris or spider webs. Clean carefully without enlarging the opening.
Step 4 – Gas valve operation (pro): A technician should verify that the gas valve receives the correct voltage during ignition and that manifold pressure rises accordingly.
Step 5 – Replace faulty components: Replace the gas valve or ignition module if they fail testing.

Note: Repeated ignition attempts without lighting can flood the chamber with gas; follow lockout and purge procedures.

Boiler’s ignition spark is visible but burner does not light.

Possible Causes