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Symptom • Burner fail to start (no ignition)

Burner fail to start (no ignition)

The booth burner isn't firing when it should.

The burner depends on proven airflow before the control will let it light. When the burner won't ignite (no flame, no warm-up cycle, an ignition fault on the HMI), the cause is either on the combustion side or an airflow permissive refusing to make. Professional service technicians diagnose ignition modules, gas valves, flame sensors, and pilot assemblies; the checks below cover the filter-side permissives worth ruling out first so you don't pay diagnostic time on something a filter change would have fixed.

Quick answer

Burner fail to start on a paint booth usually routes to combustion-system service: ignition modules, gas valves, flame sensors, pilot assemblies. But rule out the airflow side before you book the call. The burner is only allowed to light when airflow is proven, and heavily loaded AMU or intake filters can hold the airflow proof switch open or trip the air pressure safety, so the control inhibits ignition entirely. Run the filter checks below first; if media is fresh and correct spec, the resolution path is professional service.

By Ben Kurtz · Filter Fitment Lead, 20+ years in paint-booth service · Updated Jul 27, 2026
Book WERCS service for Burner fail to start (no ignition)

Why Burner fail to start (no ignition) typically needs a service call

The burner's start sequence requires proof of airflow before gas is allowed to flow. Loaded AMU pre-filters or intake filters can drop airflow enough that the proof switch never closes or the air pressure safety trips during pre-purge, so the control inhibits burner start or drops it during light-off. Check the change-cycle dates on both the AMU and intake media and read the manometer against the commissioned baseline; replace past-cycle media with the spec the booth was commissioned with. Cheaper or different MERV or CFM media unbalances the burner's airflow the same way loading does. If media is fresh, on spec, and differential pressure is at baseline, the filter explanation is ruled out and the diagnostic is purely combustion-system. Professional service from there.

Regulatory landscape

Burner faults don't directly trigger AQMD violations, but a booth that can't start can't process scheduled work, and shops that fall behind on production sometimes cut corners on filter maintenance to make up time, which leads to compliance issues downstream. Get the burner serviced promptly; keep filter cadence on the subscription.

Who runs into Burner fail to start (no ignition)

Garmat installations running Honeywell burner controls show the most frequent burner-service calls in professional service records. GFS, Accudraft, and the broader installed base see burner faults at lower rates. The brand-specific service pattern is documented in the brand pages; the symptom-level fix is service-call regardless of brand. The airflow-permissive variant clusters in shops that stretched filter changes or switched media spec after commissioning.

Burner fail to start (no ignition) FAQs

Should I try replacing filters before calling for service?

Check the AMU pre-filter and the intake filters, and replace whatever is past its change cycle with commissioned-spec media. Loaded media on either side can keep the airflow permissive from making, and that inhibit looks exactly like a burner fault on the HMI. If the media is fresh and on spec and the burner still won't start, don't keep swapping filters; call professional service for the combustion diagnostic. The service-call cost is far lower than the production-loss cost of a non-starting booth.

How long does a burner-fault service call take?

Typical burner diagnostic and repair runs a few hours of on-site time depending on the specific fault. Common repairs (flame sensor replacement, ignition module replacement, pilot assembly cleaning) are same-day. Complex diagnostic (gas valve replacement, intermittent ignition module faults) may require a return visit.

What does professional service check first on a burner fault?

Standard combustion diagnostic sequence: check gas supply pressure (covered by the gas-pressure-fault page if that's the underlying issue), airflow permissives and pressure switches, flame sensor cleanliness and signal, ignition module operation, pilot assembly condition, control sequence on the HMI. Most calls resolve in the first three checks.

Can I keep spraying without the burner if it's warm out?

For some operations, yes: unheated spray cycles work in mild ambient conditions. For finish-quality cycles requiring controlled temperature (basecoat-clearcoat with bake), no. Most shops can't operate productively on an unheated booth; the service call is the priority.

Where do I book professional service for a burner fault?

Professional service routing is available through your local booth-service provider. The service team handles the diagnostic; we don't sell burner parts.

Do filter cycles affect burner ignition?

Yes, through the airflow permissives. Loaded AMU or intake filters can keep the airflow proof switch from closing or trip the air pressure safety, which inhibits ignition or drops the burner during light-off. Off-spec replacement media (wrong MERV or CFM for the commissioned design) causes the same imbalance. Exhaust-side loading matters less for ignition but drags on overall booth balance. Fresh, commissioned-spec media takes the filter side off the table before the service call.

Sources

Primary references cited on this page.

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