Oil boiler lockout won't reset: what to do

A locked-out oil boiler is one of the most common winter call-outs we get across East Lothian and the Borders. The good news is that a lockout is a safety feature doing its job, not usually a disaster. Here is what it means and the safe steps to take before you call an engineer.

What a lockout actually means

A lockout is the boiler shutting itself down after it detects a fault, most often a failed ignition or flame. The reset button relights it, but if it locks out again the boiler is telling you something is wrong. Repeatedly pressing reset can flood the combustion chamber with oil and make things worse.

Safe checks you can do

Check you have oil in the tank, that the isolation valve is open, and that there has been no water in the fuel. Make sure the boiler has power and the room thermostat is calling for heat. If everything looks right, press reset once and wait.

When to stop and call an engineer

If it locks out a second time, stop. Do not keep resetting. The usual causes are a blocked nozzle, a failed photocell, an airlock or a pump fault, all of which need an OFTEC registered engineer. We carry the common parts and can normally get you going the same visit.