my boiler lights up everything gets luke warm then it stops the piolot light stays on but boiler fails to re ignite, some times we get everything red hot then it fails any ideas the rads have 10mm pipe apart from 1 which is 15mm i did find a empty bottle of inhibitor in the loft maybe possible problems before i know this is a old boiler and we do live in a hard water area any one got any ideas

Ray, October 2010

myson orion fanfare 40 si has a elctronic igition. when the hot water or central heating or both are set on timer. sometimes the boiler do not kick in. I can hear the fan going. other times the boiler does come on but after rest the does not fire up and I can hear the fan running.
This also happens when I do it manually too.

some times I turn it off and on again from the clock the boiler starts. if that don't work I would turn the room themodial to zero then turn it up till it clicks which can kick fire the boiler.

Do you think it's the thermocouple?

You kind advise will be much apperciated.

John King., October 2011