Boiler Genius Needed - Problem with Worcester (I think!)

James_1979

I'm not sure this is the correct forum to post a question like this so apologies if I'm wrong.

I have recently moved into a new house and it has a year-old Bosch Worcester boiler. It works brilliantly and both heating and hot water have been in constant supply whenever needed. (no heating required at the moment of course!)

Two nights ago I noticed the water from the bath hot water tap was very hot (as usual) to begin with but very quickly turned cold - well, lukewarm at best.

This was the first time this had happened so I check the boiler and the pressure had dropped to 0. It has an integral charging link so I re-pressurised the boiler and thought all was well.

The boiler has kept it's pressure. The shower continues to heat perfectly (it is also heated from boiler - not electric) but I still have the same problem with the taps for the bath and all sink taps. It starts off very hot and after a few seconds turns to lukewarm water.

I'm guessing the pre-heat feature is what's heating the water to start but why is it losing heat when the shower is still working?!

Any geniuses out there who could help?

Much appreciated.

HHarry

Could the shower be electric? If so it would only have a cold connection, and would heat the water internally on demand.

If the shower is electric, then the issue with all the other hot taps points to the boiler, but that's where my knowledge runs out and you need a plumber!

southcoastrgi

I'm not saying it is but it could be an easy fix but because you have to access the combustion chamber you need an rgi to fix

I_have_spoken

Take the spray head off the shower and see if running the water like that also means the boiler doesn't fire to heat the water

The pressure dropping to zero suggests something in the flow sensor/diaphragm failed.

James_1979

Thanks for replies - it definitely is not electric. (there is no isolator and the boiler fires every time shower is turned on)

What would the easy fix be if it was easy? Are you thinking a Power Flush is needed?

JohnB47

Experts will be along soon I'm sure but I'd be interested in what's happening in the boiler when you turn on the hot tap at a sink. Is one nearby the boiler? I would watch and listen to the boiler as you slowly increase the flow from the tap.

Can your tell us what happens?

To my mind, the only difference between using the shower and using a tap is that a tap is likely to draw more water through the boiler. Maybe your water pressure is so high that your boiler simply can't keep up with it and it starts off well, when the water initially is warm but then the incoming water cools down and the rate through the boiler is too high for it to heat adequately. To test that, turn on a tap just enough for the boiler to fire up, then leave it at that point. It should come through very hot. If so, increase the flow and watch the boiler. If it's still firing but the water gradually gets cooler, then reducing the water pressure might help.

ollski

Possibly have your shower mixer temperature set a little lower in this weather and with a lowish flow rate it wont need as much hot water as a tap. Feel a couple of radiators after you have a tap running 5 or 10 minutes and see if they start getting warm.

adandem

Get wb out, it's under warranty at that age.

miss.average

Hi James_1979
I too am having trouble with my Worcester boiler ( 21 months old!) - so am watching all the answers with interest! Mine has pressure etc but there's no green light on - under the lid and the boiler just won't fire?
Like you I've reset and reset and now feel like I've broken it. OMgoodness and all I can see is £££ signs, - No hot water is killing me!
Hope I haven't hijacked your post.
good luck

daveyjp

Why are people with newish boilers not simply calling the WB warranty helpline and waiting for the engineer to call round, rather than expecting people on the net to guess the problem?

southcoastrgi

Because I'm guessing it's not a Warentee issue & therefore the OP is likely to get charged by WB