Technical directory · Combustion
Igniter contamination
Hot-surface igniters are fragile and may fail without visible dust; a gas ignition issue is not a general cleaning job.
What to observe
Record model, fault code and what sequence occurs before heat fails.
A field example
An igniter that does not glow can be failed, unpowered or prevented from receiving a call by another safety control. Testing the sequence is more useful than assuming dust is blocking heat.
What the written work should say
A qualified gas technician should test the ignition system and replace approved parts where indicated.
Where this task stops
Do not touch an igniter, bypass a safety switch or restart a faulting furnace indefinitely.