Why is my hot water only lukewarm, but radiators are boiling hot?

[Michelle1972]

Hello,

I have a Baxi WM boiler which lives in my loft, which is working normally. This afternoon I have discovered my hot water seems to be virtually non existant, but the radiators are scorching hot. Everything was fine yesterday so not sure whats gone wrong

I turned the heating off leaving the hot water on, but after a while the radiators made noises like they had no water in them (if that makes sense...though they do have water in!). The hot water seemed to heat up a bit more though after that.

Later when I turned the heating turned back on the water cooled right down, so what could be the problem?
The hot water cylinder is only 5 or so years old. I really don't know much about plumbing. I have an 'Immersion Heater' switch which is also for heating water in the cylinder....correct? Why do you need one of these if the water is heated throught the boiler?? This is switched off though, has been for years.

Not sure if its connected but my very old shower 'Triton T80' is now set at No.8 to get the water to come out as hot as I'd like it.....guess this is due to its age?

I had problems recently with banging and juddering pipes and after investigating I found that I had knocked the switch on the pump from 2 to 3 so it was working full speed. Everything fine with that now I hope.
Any advice greatly appreciated, though I don't understand plumbing talk so try and make it as simple as possible....Blonde nad very dumb....Thanks

 

[oldplumber]

could be a motorised/diverter valve problem so best to call in a plumber to see whats wrong and resolve the issue

 

[Michelle1972]

Hi,
Thanks for the quick reply....do you advise I put this Immersion Switch on for now then to get the water hotter?

 

[Dotty]

Yeah but only for an hour, cost too much otherwise. As OP says it sounds like you've a motorised valve problem. Whereabouts are you and perhaps one of the chaps on here could give you a visit.

 

[Michelle1972]

Thanks for the quick response....what makes them think it could be motorised valve problems? What does that entail as to fixing the problem? Sorry I live in the UK ...Rugby in the midlands....bit far away!

 

[Dotty]

Lol I kinda knew you'd be mainland, most everyone is! What we believe is happening is that the 3 port, or diverter, valve has failed in one position, sending your hot water from the boiler round your rads rather than the coil in your hot water cylinder.

Rugby.... Ahhhhhhhhhh!!! Had a few pints there once when I was on a course in Coventry. Talking many moons ago lol.

 

[GrahamM]

The motorised valve open and close as per the demand for heating and hot water.
There are various designs of this system. Sometimes one valve, sometimes two. If your hot water valve is not opening or only partially opening you will get limited hot water. Some valves the mechanical head is replaceable- 20-30 min job. Some valves will need whole unit replaced and a system drain down will be required- this will be fair bit longer.

 

[Michelle1972]

Sorry Croppie.... what will the plumber do to fix this and how much is it likely to cost? And typical everyone appears to be so far away.

And yes Rugby is pants!!!

 

[Michelle1972]

Thanks for this info...is it likely to be costly?

 

[Michelle1972]

Is this also why then when i don't want the water on but just the heating the radiators don't get very warm?

 

[Bartdude]

You should have one of these

Diverter valve

Or 2 of these

Motorised valve

Which system do you have?Look at the pipes near the hot water cylinder

 

[Michelle1972]

I have one of the top ones (diverter valves)....what will it cost to fix or replace?

 

[SafeGasInstall]

ask your local plumber,i think he would be able to give you the right answer and the invoice for it !!!

 

[Michelle1972]

If I could get one I wouldn't be on here!!!

 

[SafeGasInstall]

why,you run out of £?