boiler switch off automatically

[ramkmr]

Hi
I have Potterton boiler which used work for few months ago very well till this summer then I changed the all radiators
now the boiler works and heats very well then switch off automatically
I have to ignite again then will work for some time then switch off automatically
any ideas where the fault could be
Thanks a lot

 

[ChrisR]

Air lock - overheating.

 

[ramkmr]

hi chris
thanks for your reply
can you little bit tell more
is that air lock in boiler or radiators or to be done for whole system

also the Hot water works perfectly
the central heating if switch on (say room temperature 10C then I turn on to 20C) so it start working on but when the temp is more than 20C in room the boiler don't know this so it keeps heating on and at the end the ignitions switched off automatically
also if I turn the temp to 10 as soon as the room temp reaches to 20 then there is no problem at all
Thanks for your help

 

[Breesey]

Could be the central heating thermistor or the diverter valve, or both.

Also check that you have no leaky hot taps or shower. If you do fix them.

I'm assuming you have a Potterton Combi, you didn't say. let us know.

 

[ramkmr]

hi there is no leak anywhere
I am having potterton falmingo 50 conventional boiler

 

[Breesey]

This is probably an old boiler. If the heat exchanger is scaled up this will reduce the amount of water in it thereby increasing the speed with which the boiler stat reaches temperature and then shutting down.

Does the pilot also go out?

When did you last get the boiler serviced?

 

[ramkmr]

serviced about 2 years ago
yes the light(Is that the pilot?) also goes down
then i have to ignite again

 

[Breesey]

Get it serviced NOW.

Should be done annualy. The chap you get to do it will also fix it of course.