BillR secured a place in history by writing:

Modern boilers have lots of safety checks built in. Maybe one of them was
triggered?
e.g. flue seemed blocked due to string wind or high level thermocouple
tripped.



Interesting - do these things generally 'uncheck' after the problem has
gone away?

Only change in the norm I could point to is that it's rained without
stopping for almost 48 hours here.

--
F