Worcester CD26i Xtra Combi Boiler Issue

[grs18]

Hi, Looking for some advice as to what the following issue may be. We have a Worcester CD26i combi boiler (about 7 years old) and within the last couple of weeks we are struggling to get hot water upstairs, the taps just run cold (sink, bath and shower). However, when the heating is on we get hot water to the upstairs taps. Heating on or off the downstairs taps produce hot water fine. It's only started within the last couple of weeks - anyone got any ideas as to the problem?

Cheers

 

[tipintim]

You could have a check valve jammed and cold water is mixing with hot. Have you got a mains fed shower mixing valve?
If yes, can you isolate shower and then test. Dont think its a boiler problem imho.

 

[grs18]

erm, maybe....:smilewinkgrin:, the shower (a gainsborough ambassador mixer) is supplied from the same source as the upstairs sink and bath. Sorry to be so dumb but where might the mixer valve be!!??

 

[grs18]

ok, have isolated the shower supply but water still runs cold to both the sink and bath, any other ideas!!??

 

[SafeGasInstall]

kitchen sink !!!

 

[grs18]

oh yeh!! Same result though, hot water not coming through upstairs?

 

[SafeGasInstall]

put hot water on and see if the ch pipes are getting hot under the boiler

 

[tipintim]

Is the basin a mixer tap? Isolate this and test.
If you have fine hot water down stairs, there should be no reason that upstairs be fine. (there must be something mixing upsairs ?)

Does the boiler fire when you draw water off upstairs?

 

[grs18]

Put hot water on (downstairs) and CH pipes get hot and we have hot water. Upstairs hot water on, CH pipes not getting hot and boiler not firing

 

[grs18]

Hi tipintim, no the basin or bath are not mixers, just the shower. The boiler isn't firing when the hot taps/shower are on upstairs

 

[SafeGasInstall]

you need to call your local gas safe register engineer or

post here [DLMURL="http://www.ukplumbersforums.co.uk/im-looking-plumber-gas-engineer/"]I'm looking for a Plumber or Gas Engineer[/DLMURL]

 

[tipintim]

Sounds like diverter (jammed), but you get hot down stairs?! Beats me without seeing it. What area are you?

 

[grs18]

Manchester

 

[GrahamM]

Almost definitely the divertor valve assembly.
Need this changed by a competent person. Bit awkward on these boilers so call a local engineer.
Get the plate heat exchanger cleaned out while it is off.