low hot water from my boiler HELP!

[richtam]

im getting luke warm water from my boiler in demarnd for hw, sometimes its hot but not for long, the presure goes up and then ignition goes out and i get some bangin noise then the presure drops and it ignites can some one help me on this thanks

 

[twgas]

do you have a white one on the wall

 

[mickyg]

Hot Water issue sounds like a plate heat exchanger fault but banging ang pressure rise sounds like a main heat exchanger fault. Could it be you have a dual pass heat exchanger? boiler model please

 

[richtam]

its a worcester 24cdi thanks

 

[mickyg]

hmm..that has a plate he as far as i can remember so there goes one theory...Hot water fluctuations usually are caused by blocked plate he's. However try your heating and see what happens including what happens on the pressure gauge(assuming its set 1-1.5 cold already).

 

[richtam]

ch its all working fine!

 

[richtam]

only happins in hw demand, could it be the hw sensor but would that explan the bangin noise?

 

[mickyg]

I would say plate heat exchanger most likely. if it were almost completely blocked it will explain the banging.

 

[richtam]

would the heat exchanger need replaceing? thanx for your help

 

[mickyg]

would the heat exchanger need replaceing? thanx for your help

You can try flushing it out. uite often works or at least makes an improvement, but rarely a long term fix. Bit of a nuisance on these to be honest, the isolation valve always leak so don't touch them, as they are a pig to change.
Also the top left hand rubber washer always leaks afterwards so I would get a new one of them as well before you attempt anything.

Are you intending to do this yourself?

 

[richtam]

yes i am! ive done some work on it over the years like the diaphram ive replased twice and other bits like that, you ovusly know a bit about this because my isolater did leak and the washer is a pig to stop it leaking