Combi Boiler Help

Alex1983

Does the boilers flame light go out while the bath tap is running? Any fault codes on the boiler display?

Try running the bath and basin tap at the same time, does the bath tap stay hot then?

oddjobbpb

Are your showers electric and is that why they are OK?

It sounds like a blocked hot water heat exchanger, new one generally £150 or so plus fitting.Not a diy job AFAIK

harz99

Is there not a thermostatic control built into the bath hot feed for modern bathrooms, to prevent the tub being filled with scalding hot water?


Whoever fitted your new bath etc. should be able to confirm that, and whether it is possibly faulty.

naf123

Is your bath tap a mixer valve sort ? Could be the valve is broken ?

southcoastrgi

An answer to post #2 & #12 would help

macman

karatepet wrote: »

Does the boiler allow you to control the water and heating seperate?
If i have the water on the heating is turned off until the water is turned off.

All combi's do that: opening the hot tap makes the diverter valve switch 100% of the flow to the DHW circuit, and none to the CH.
I'd suggest that there's a problem with the flow rate or pressure to the bath, causing the burner to cut out soon after the bath tap is opened. So you need a plumber, not an RGI.

AbbyCarr98

Hi, I do not know if the shower is electric. How would I know? We didn't have the bathroom installed, it was the previous owner. Just tried running bath taps now. Boiler light comes on, hot water comes out. Cold water then starts running but boiler light still on and no fault codes on it. Running the bathroom tap at the same time, stops it going freezing cold but it's barely lukewarm I would say when both running. Our bathroom taps will run scalding for as long as we would want, they never run off cold and they're not electric

AbbyCarr98

The bath has a hot and cold tap but the water is mixed. If I just run the hot, it runs scalding and then freezing cold. I assume the shower is not electric as the boiler comes on when the shower is running.

Alex1983

When the radiators are cold run the bath tap for 10/15mins and make sure none of the radiators get hot.

Assuming that they don't and the boiler flame light stays on the whole time then I would think you have to be running your bath tap to fast or the mixer is faulty.

AbbyCarr98

The flow from our shower I suspect is far greater than the flow from the bath tap. The shower head is one of those extremely large waterfall type ones. We can use this easily and receive extremely hot showers for as long as we please. Changing the flow from the bath tap does not make a difference to the time that it runs hot for. If it was the flow, wouldn't the water just not be as hot, rather than freezing cold?