Worcester 28CDI - Supplying lukewarm water

[tattyt]

Hi,

I was wondering if anyone could help me:

I have a gas Worcester 28cdi which is only supplying lukewarm water.

This happens all the time, even though the heating is still working fine. The water demand light is on.

We have recently had the plumbing put in for a new bathroom.

This problem has only just started.

Any advice would be extremely appreciated, I have been searching the internet for answers.

Thank you

Tattyt

 

[fitz1]

has the cold main flow rate been increased ? Is the burner pressures o.k ? have you a faulty thermistor ? etc etc

 

[gas4you]

Are all hot taps like this now or just bath? Did bathroom guys fit 22mm pipe to bath hot tap when it used to be 15mm. Combis only like 15mm take offs

 

[tattyt]

Thank you very much for the quick responses.

Some answers:

has the cold main flow rate been increased ? No

Is the burner pressures o.k ? yes 1.2 bar

have you a faulty thermistor? No

Are all hot taps like this now? Yes

Some more information:

When the heating comes on the heating light comes on + the burner light. When you turn the hot water on, no lights come on however if the heating is already on then the hot water light comes on but is lukewarm.

The new bathroom is not actually working yet.

Hope this helps,

Tattyt

 

[gas4you]

diaphragm or blockage in the same. if you've got 1.2 bar burner pressure then strap yourself in 'cause next stop will be the moon

 

[tattyt]

Spot the amateurs

Tattyt

 

[tattyt]

Thanks for your help so far, I am not sure where the diaphram is located or how to change it - advise would be appreciated. I am a fairly good DIY'er, I changed the Combustion Air fan of this boiler last year.

We have made some progress and I can now provide a full fault explanation.

WB 28CDi Gas boiler, about 4 years old.

C/H - working fine

H/W - water is tepid from all hot water taps.

When I first noticed the problem, the hot water indicator light was not coming on and the burner light was not coming on, therefore the water from the hot water taps was cold. I also noticed that the flow rate from the hot water taps was higher than normal.

So I then power cycled and reset the boiler.

Then when I next tried the hot water it just so happened that the CH was on and therefore the burner was on. This time when I turned on a hot water tap the hot water indicator came on - fixed it I thought - but NO. The water was tepid, warm at best.

So, next I ensured the CH was OFF and tried a hot water tap again, this tme the burner fired up and the hot water indicator light came on (I also checked that the burner was actaully on - it was). Again the water was just warm (not hot).

Do you still recommend changing the diaphram - if so, where is it located? can a DIY'er do the job?

Thanks..................

 

[namsag]

Not by any chance crossed the hot and cold supplies to the combi while altering the bathroom pipes.

 

[ChrisR]

Get the manual from the WB site, Do a search here.
Look for the pin movement

Search here and you'll see that most pros change the whole diverter valve. You could strip it down and clean /lubricate it and have the whole job done for about £35 in rubbers etc.
But first time, it'll take a few hours, and probably leak.

Or pay a pro 200 or so and have a new diverter.