In message
,
cynic writes

snip

Starting ok then dying would fit with a clogged filter.

Strange. Yesterday, I turned off the heating, due to the odd noises the
boiler was making, before cutting out. However, I left the HW to come
on early morning, fully expecting that it would cut out, so I set the
immersion heater timer, too.

This morning, the boiler had not cut out, so I tried the heating.
Perfect. Been running all day, and did not cut out until an hour ago.
Reset, and running fine again. An intermittent fault. Oh joy.
--
Graeme