Lochinvar Boiler: Won't stay lit
When a Lochinvar boiler lights but then drops out within seconds or minutes, the flame-sensing (rectification) circuit is losing the flame signal — often a dirty flame electrode, unstable gas pressure, or a combustion problem.
When a Lochinvar boiler lights but then drops out within seconds or minutes, the flame-sensing (rectification) circuit is losing the flame signal — often a dirty flame electrode, unstable gas pressure, or a combustion problem. On Lochinvar boilers, this is linked to 2 fault codes (Ignition Failure, Flame Loss). Below are the likely causes, the safe checks you can make, and exactly what our licensed BC gas technicians do — because boiler repair in British Columbia is licensed gas work, not a DIY job.
This is a gas-safety fault. Diagnosing ignition, flame, gas or venting problems requires combustion analysis and gas-pressure testing that, by BC law, only a licensed gas technician may perform. Never bypass a safety lockout. Smell gas? Leave the building and call 911 or FortisBC at 1-800-663-9911 from outside.
What you might notice
- Boiler fires briefly then shuts down
- Intermittent heat or hot water
- Short-cycling with lockouts
- No heat or no hot water
- Boiler attempts to fire (you may hear clicking) then locks out
- Repeated lockouts after a few ignition attempts
Safe checks you can make first
These are the only steps a homeowner should take. If they don’t resolve it, stop — the rest is licensed gas work.
- 1Note how long the boiler runs before it shuts down
- 2Check the display for a flame-loss or ignition fault code
- 3Confirm the gas supply is steady (no other appliance starving it)
- 4Do not keep resetting — repeated flame-loss lockouts need combustion analysis
Related Lochinvar fault codes
These Lochinvar codes are commonly behind “won't stay lit”. Tap any code for its full meaning, causes and fix.
What our licensed technicians do
- Measure flame-rectification current (microamps) during firing
- Clean or replace the flame-sensing electrode and check its ground path
- Inspect the burner and heat exchanger for sooting or fouling
- Verify gas pressure and re-run combustion analysis
- Verify incoming gas supply and lock-up/working gas pressure with a manometer
- Inspect and clean the igniter and flame-sensing electrode, checking the spark gap
Lochinvar won't stay lit — FAQ
Why does my Lochinvar boiler light then shut off?
When a Lochinvar boiler lights but then drops out within seconds or minutes, the flame-sensing (rectification) circuit is losing the flame signal — often a dirty flame electrode, unstable gas pressure, or a combustion problem. The related Lochinvar fault codes are Ignition Failure, Flame Loss. A licensed technician confirms the true root cause with the right instruments before any repair.
Is it safe to keep resetting my Lochinvar boiler when it shows "won't stay lit"?
No. A single reset after a one-off event is fine, but "won't stay lit" involves gas, ignition, flame or venting safety. Repeated resets without fixing the cause can be dangerous and can damage the boiler. If the fault returns, switch the boiler off and call GasBoilers.ca at 604-359-1081. If you ever smell gas, leave the building and call 911 or FortisBC at 1-800-663-9911 from outside.
Can you repair a Lochinvar boiler with this problem in Greater Vancouver?
Yes. Our Red Seal–certified, TSBC gas-licensed technicians diagnose and repair Lochinvar Knight, WHN and SMART System series across Vancouver, Burnaby, Surrey, Richmond, the Tri-Cities and the rest of Greater Vancouver. Same-day appointments are often available — call 604-359-1081.
“Won't stay lit” on other boiler brands
Lochinvar boiler won't stay lit? We can help today.
Licensed, Red Seal–certified gas technicians across Greater Vancouver. Upfront pricing, same-day service available.