On Monday, 15 February 2021 at 14:16:15 UTC, The Natural Philosopher wrote:
Boiler:
Camray 5 circa 2001, oil, non condensing

Symptoms:
It seems to be on, and yet it hasn't fired. Sometimes after tens of
minutes it does, and then works fine.

The flameout/lockout *doesn't* come on. (although it did twice in the
high winds)

There is oil in the tank


http://vps.templar.co.uk/Odds%20and%...Camray%205.jpg

It sounds as though the oil pump and air blower are doing their stuff.
Not sure about circulation pump, but water is cold.

Any ideas?


--
Theres a mighty big difference between good, sound reasons and reasons
that sound good.

Burton Hillis (William Vaughn, American columnist)
Coming late to the party but if the boiler is a low level flue version it may have an auxiliary run-on timing circuit which operates the motor and fan to purge the combustion chamber of fumes at the end of a flame demand cycle so in adverse wind conditions the ball of flame and hot gas in the chamber wasn't blown backwards into the burner leading to burnt photocells and stink in the room. These had a failure mode where the motor and fan would run indefinitely but no ignition attempt was forthcoming.