pilot light on but no heat?

It is difficult to say if it's a big job or just something simple - it will probably cost more than you expected whichever it turns out to be.

Some boiler engineers are very good and some just make guesses at your expense - they may tell you that more than one part was at fault to justify replacing several items. Some repair companies - the larger outfits - get rich on "up-selling" - encouraging you to have supplementary work done at great expense.

Before you engage an engineer you will do well to ask about his diagnostic skills - ask him the direct question, "Do you just change things willy-nilly until it works?"

Ask him (her), "If you change an expensive item like a £300 gas valve for instance - and it's not that causing the problem - who pays for your diagnostic error?"

The first thing any engineer will do is to check to see if there's a "call for heat" i.e. Is there a signal from the timer and the room thermostat asking the boiler to fire up? Then he will check the fan etc in a logical process.
He will not say, "it's most likely the timer" until he's sure.

Good luck...

Peccavi
March 2013

its most likely the timer is faulty as it controls the boiler even if it shows it on. it maybe faulty inside. point out to the plumber to bypass the timer to see if it works. let me know how u get on. he can also check to see if there is power to the boiler. if there is power to the boiler then i suspect a problem with the boiler. try websites like my builder where plumbers have reviews and u can leave reviews after

kash
March 2013