Boiler keeps locking out after a reset
A one-off lockout after a power cut is normal. A boiler you reset every morning is telling you a component is failing under load — and each reset sends it back into the same failing cycle. Repeated resets on oil burners in particular can flood the combustion chamber.
Why resets stop working
Lockout is the boiler's last safety step. On gas it usually follows failed ignition, overheat, or a blocked condensate. On oil it follows photocell failure, a clogged nozzle or contaminated fuel. The reset clears the memory but not the cause, so the interval between lockouts shortens until it won't restart at all.
Common repeat-lockout causes we find
- Blocked or frozen condensate run causing overheat trips
- Sludge in the primary circuit driving heat exchanger overheat
- Oil nozzle past its service interval, or water in the tank
- Failing fan producing intermittent air-pressure switch faults
Stop resetting an oil burner repeatedly
Each failed oil ignition attempt sprays unburnt kerosene into the chamber. Two resets is the sensible limit — after that call an OFTEC engineer rather than risking a rough light-up.
Frequently asked
- How many times is it safe to reset?
- Twice. If it locks out a third time, leave it off and book a visit.
- Could it be the thermostat?
- A faulty room stat causes short cycling rather than lockout, but rapid cycling accelerates overheat trips, so we check controls as part of the same visit.
- Will a power flush fix it?
- Only if sludge is the confirmed cause. We measure system water and check the filter before recommending one — we won't sell a flush on suspicion.
What we leave you with
A written diagnosis naming the failed component, the repair price, and an honest view on whether the boiler is worth spending on given its age and parts availability.
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