Explosion or loud bang during startup: delayed ignition and what to check

A loud bang during ignition may indicate delayed ignition. This is a serious symptom and should not be ignored or covered up by repeated resets.

Delayed spark

Incorrect electrode position, a worn cable, or a weak transformer can delay ignition.

Excessive gas quantity at startup

An incorrect start position on a valve or servomotor can create an overly rich mixture before a flame appears.

Pilot

In systems with a pilot, a small or unstable pilot flame can delay the ignition of the main flame.

Pre-purge

Verify that the pre-purge completes correctly and that there is no residual fuel in the chamber.

Safety

In the event of repeated delayed ignition, the burner must be checked before continuing operation. The cause can cause severe stress to the combustion chamber.