Hot water not working on Oil boiler. Only works when CH on

Hi there,

Firstly let me say this site is a mine of info so well do!!!

My problem is probably fairly simple. i have a bog standard CH system. It is an oil boiler, with a hot press and 2 tanks in the roof. Usually i run it on the Ch/HW setting and all the radiators work and the water heats up. Tickety boo.

Now that we are in summer time i just want to run the system to heat the water only. When i do this the boiler runs for about 10 mins and the pipe coming out of it get hot and then the boiler shuts off and doesn't come back on again.

I followed the pipe into the house and up the stairs and it runs up past the immersion heater and up into the roof. However the pipe is hot until it gets just up past the immersion and then goes cold before it goes into the roof.

I cant see anything that looks like a motorised valve or anything?? Why would i have no hot water?? Would it be an airlock?? Also can someone gives me an idiots guide to how mys stem works??

Thanks in advance guys

Sean

check the header tank has water in it

Hi kev and cheers for the swift response.

The header tank is full of water and working fine

Sean

Still no hot water guys. any advice????

Cheers

Sean

blocked cold feed
or
sludge .
or
maybe the tank coils are limescaled up real bad.

i presume your hi limit stat aint coming on on the boiler is it?

Is the pump working in hot water mode or are the primaries gravity

Hi there,

The pump does not run when in hot water mode so i assume it is all gravity fed. It is quite an old system.

Back over to you!!!!

Sean

Hi guys,

I have been going through the site trying to find a solution. Vould it possibly be an airlock?? Or would this still apply when the central heating was on. I am baffled now to be honest.


PLease help!!!!

Sean