One reset after checking power and pressure is reasonable. A lockout that keeps returning is the unit telling you a real fault exists underneath it.
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Quick answer
A Lochinvar Noble Combi lockout means the control has detected a condition it treats as unsafe to keep running through, such as an ignition failure, a pressure problem, or an overheat condition, and has shut the burner down as designed. A soft lockout may clear on its own or with a single manual reset once the underlying condition passes; a hard lockout, or one that returns quickly after reset, means a Technical Safety BC licensed gas fitter needs to identify the actual fault rather than the unit being cycled repeatedly.
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A lockout is not a malfunction in the sense of something breaking; it is the control doing exactly what it is designed to do when it sees a condition outside safe operating parameters. Ignition failure, loss of flame signal after ignition, low water pressure, high limit or overheat protection, and blocked venting are the categories that most commonly trigger a lockout on a condensing combi boiler. The control does not tell you which specific part failed; it tells you which category of problem it detected, and a technician's job is narrowing that category down to an actual component.
Some lockouts are soft, meaning the control will retry or clear automatically once conditions return to normal, such as a brief pressure fluctuation. Others are hard lockouts requiring a manual reset, and those exist specifically because the condition detected is serious enough that the system should not just try again on its own.
A single reset attempt, after you have confirmed the unit has power, the system pressure gauge reads normally, and the gas shutoff valve is open, is reasonable. What is not reasonable is resetting it two, three, or more times in a row hoping it eventually sticks. If a lockout returns within minutes or hours of a reset, that is the system telling you the underlying condition is still present, and repeated resets do not fix anything; they just delay the point at which a technician gets called, sometimes making the pattern harder to describe accurately once they arrive.
| Situation | Reasonable homeowner action |
|---|---|
| First lockout, unit was running fine before | Check power, pressure, gas valve; one reset is reasonable |
| Lockout returns within minutes of reset | Stop resetting; book a diagnostic visit |
| Lockout accompanied by gas smell or hissing | Leave the home; call FortisBC, not the reset button |
| Lockout during or right after a cold snap | Check condensate line for freezing before resetting |
Where a reset just tells the control to try again, a technician's diagnostic process actually measures the conditions that caused the lockout in the first place: gas pressure at the manifold under load, flame signal strength at the sensor, water pressure and expansion tank precharge, and airflow through the intake and exhaust venting. That measurement step is what turns a repeated guess into an actual repair, because it identifies which of the lockout categories was really at fault rather than assuming the most common cause.
This is also why we do not recommend homeowners try to interpret a fault history on their own beyond the basic checks above. The display narrows the search for a trained technician; it is not a substitute for the measurements a technician takes on site.
As a 2026 public-market ballpark, not a quote, a diagnostic visit for a recurring lockout typically runs $90 to $150, usually credited toward the repair once the fault is identified. Depending on what is found, the repair itself commonly falls between $250 and $1,800, with most straightforward jobs, such as an ignition component or a flame sensor, landing between $400 and $900. CANRO's certified technicians will explain which lockout category was involved and what specifically caused it, rather than leaving you with just a part name on an invoice.
If the lockout turns out to be related to venting or gas supply rather than a component inside the boiler, that can widen the scope of the visit, which your technician should explain before proceeding rather than after.
Safety note
A lockout accompanied by a gas smell, hissing sound, or soot near the vent terminal is a safety issue, not a troubleshooting step: leave the home and call FortisBC at 1-800-663-9911 immediately. Diagnosing the actual cause of a recurring lockout must be done by a Technical Safety BC licensed gas fitter.
A soft lockout can clear on its own once the triggering condition passes, such as a brief pressure dip. A hard lockout requires a manual reset and generally indicates a more serious condition, such as a flame or overheat fault, that the control will not simply retry on its own.
One reset after checking the basics, power, pressure, and the gas valve, is reasonable. If the lockout returns quickly, stop resetting and book a diagnostic visit rather than continuing to cycle the unit.
Yes. Some faults, like a sudden ignition component failure, can cause a lockout with no gradual warning. Others, like a slowly failing flame sensor, may cause intermittent issues before a full lockout occurs.
A lockout itself means the safety system worked as intended and shut the burner down; it does not necessarily mean there is an ongoing hazard. However, any accompanying gas smell or unusual sound should be treated as a safety issue regardless of the lockout status.
Cold snaps can freeze an exposed condensate line or push gas and water systems closer to their limits under higher heating demand, both of which can trigger a lockout that would not occur in milder weather.
Yes, after diagnosis our technicians explain the specific category and component involved rather than leaving you with only a general description, so you understand what was actually fixed.
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