Ignition Faults We Diagnose & Repair
No spark from ignition electrode
Spark present but no flame — fuel or valve issue
Flame sensor / ionization rod failure
Gas valve not opening — diagnostic and replacement
Inducer motor failure (no air proving)
Pressure switch fault — blocked or failed
Control board / PCB failure
Intermittent lockout — hard to reproduce faults
Navien E003 and E012 fault codes
NTI ignition fault codes
Standing pilot light won't stay lit (older boilers)
Blocked flue causing safety lockout
Boiler Not Working Right Now?
Call directly for same-day emergency response across York Region. We carry common parts on the truck.
📞 647-699-2474Our Repair Process
- Write down the fault code — before calling, note any code showing on the display. Don't reset more than once. The code tells us exactly which safety circuit triggered the lockout.
- We arrive with a full ignition kit — electrodes, flame sensors, gas valve test equipment, manometer for gas pressure, and a combustion analyzer.
- Gas supply verification — first thing we confirm is adequate gas pressure at the boiler inlet. Low gas pressure from the utility side or a partially closed supply valve causes most 'ignition failures' that aren't actually component failures.
- Ignition sequence test — we manually step through the ignition sequence: inducer on → pre-purge → spark → gas valve open → flame confirmation. This pinpoints exactly where the sequence fails.
- Component replacement and recommission — failed component is replaced, system is recommissioned with a combustion analysis, and the fault history is cleared.
Common Questions
The gas being 'on' at the meter doesn't mean adequate pressure is reaching the boiler. Check that the manual shutoff valve on the gas line to the boiler is fully open (handle parallel to the pipe). If that's fine, the fault is usually the ignition electrode (worn tip, cracked ceramic, incorrect gap), a failed flame sensor, or a gas valve that's not opening on signal. We test all three in sequence.
This is a flame loss fault — the boiler ignites successfully but loses flame shortly after. Common causes: a dirty or failing flame sensor (ionization rod) that can't confirm the flame is established, a weak gas valve that loses pressure under load, or a heat exchanger blockage that causes the high limit to trip. The flame sensor is the most likely culprit and is a quick, inexpensive fix.
A frozen condensate pipe is the most common cause of boiler lockout in Ontario winters. The condensate pipe (usually white plastic, runs from the boiler to a floor drain or exterior wall) freezes at the exit point. You can thaw it carefully with warm — not boiling — water poured slowly over the pipe. Once thawed, reset the boiler once. If it fires, call us to re-route or insulate the pipe so it doesn't refreeze. If it won't fire after thawing, call us directly.
Intermittent overnight lockouts are almost always related to condensate freeze (most common in winter), a failing component that drifts out of spec when cold, or gas pressure fluctuations overnight when utility demand is lower. The condensate freeze scenario is particularly common — the pipe freezes at 2am, the boiler locks out, and by 7am it's thawed and resets fine. We can diagnose intermittent faults by checking fault history memory on the boiler's control board.
One reset is fine — it clears a fault that may have been transient (like a momentary low pressure event). More than two or three resets without knowing why is not safe. Lockout codes exist to protect against dangerous conditions — repeated resets bypass those protections. If your boiler is locking out regularly, call us. Don't reset it more than once.
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G1 licensed, Navien and NTI certified. York Region's owner-operated boiler specialist — the tech who answers is the tech who shows up.
- ✓ G1 Licensed — all gas boiler work
- ✓ Navien & NTI factory certified
- ✓ All brands and boiler types
- ✓ Same-day for emergencies
- ✓ Upfront pricing — no surprises
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Free estimate — York Region