Oil-fired boiler fires, runs for 75-150 seconds, cuts out

Worcester Danesmoor 26/32 from 1996, serviced earlier this year. Fires, but the lock-out light comes on after 75 seconds or more. Possible slight change in the firing noise about 15 seconds before the light comes on. Plenty of oil in the tank. Lock-out can be re-set after a min or so, and then it goes through the cycle as above all over again.

Suspicions are the photocell and the solenoid coil. The latter went a few years ago.

Ideas? Many thanks in advance.

Could be photocell or control box,solenoid coils normally breakdown when hot,but you never know.

If the firing noise changes prior to Locking out, this indicates Fuel Starvation, check your valves are open, check the fire valve is correctly open, DOUBLE check that you havn't run out of oil, and finally check the oil filters, if this dosn;t work call an Oil service engineer

is there a sight hole somewhere? so you can see the flame? most boilers have.

you need to find out if the flame getting cut becasue of a fault or if the flame is actually going out, hence lock out.