water flucuates from hot to cold then back to hot ...

[Jomo]

Hello!

Over the past few months my hot water supply to all taps in the flat has been flucuating from hot to cold. It is quite consistant and slowly changes from hot to cold then back to hot again. Also the heating seems to be really hot at the moment - maybe that's something to do with it.

I have a Vaillant combi boiler (model number: VCW-GB 242 EH) ... I have had a plumber look at it and he said we may have to replace the boiler - I'm terrified of being conned by a cowboy and would appreciate any advice

please help!

Jo

 

[Rob]

run a tap at a low rate and watch/listen to the boiler if its firing up dropping out firing up etc then probably blocked HE. still available but is a different design, supply and install £200 approx?

 

[Jomo]

thanks for reply!
what does HE mean?
and do you mean I'd have to replace the whole bolier or just a part

thanks again x

 

[cross thread]

i would suspect gas settings are incorrect why not get a trained combi specalist not a plumber to look at it

 

[GH blackpool]

AHA!! Maybe I can add to this - even though I know nothing about anything building/electric/plumbing/gas related!

I have a similar problem now and again. had thermisters replaced last friday, but had to have the engineers back out yesterday as I'd been left with a leaky filling loop. On refilling the system, this problem was encountered when testing the hot water.

The engineer diagnosed (now bear with me, I can't remember the exact name...) that the gas regulator (?) wasn't working. He said that once something inside gets to a certain temp, the gas regulator should cut back on the gas being used, then increase, decrease etc as is required. On mine, he thinks that this isn't happening so the water is getting too hot and it's just cutting out completely, cooling with new water (unheated) then starting over.

Would this be anyhting like you were suggesting, gordongas?

PS hello to a fellow blackpudlian!