On Monday, 9 January 2017 17:05:36 UTC, Grumps wrote:
On 09/01/2017 16:51, charles wrote:
In article ,
Grumps wrote:
Happy New Year etc.
Brexit, Daesh, Trump etc, blah blah, but more importantly my boiler is
having issues.

No hot water this morning and it was evident that the boiler (a 30 year
old Potterton) was off.
It restarted OK and ran for a few minutes.

I changed the thermocouple but it behaves the same.
In fact, if it's just the pilot that is on, then it stays on. It's only
when the burners start that it shuts down after about 2-3 minutes.

Any ideas or is it time to call a man in?
Ta.

Mine - of similar vintage (1988) but not Potterton - suffered a similar
problem a few years go and it was found (not by me) to be a faulty overheat
sensor. It was simply bypassed until a new one was fitted.

So when your overheat sensor triggered it shut down the whole boiler,
pilot and all?
How do they work? If I disconnect it will the boiler work or stay in
shutdown?
I see what looks like another thermocouple lead going to the top of the
boiler.

A metal bulb containing liquid expands when heated, pushing itself down the capillary tube and opening the switch.


NT