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 £?

 

[P/Boro Plumber]

Hi, from what you say the most likely thing is like the previous guys have said is a motorised valve is faulty, there are many types some can be repaired but otherwise it may need replacing. As you are having problems with your heating also I wonder if you might have a blocked cold feed which would mean that the system in running dry of water (not uncommon). You need a plumber to fix whatever it is I would suggest. Shouldn't take more than 1 or 2 hours and the most expensive part would be a new motorised valve if that's what is required (cost to us guys up to £60). In the meantime it should be ok for you to use the immersion heater to get some hot water, that should be thermostaticly controlled so should turn itself off when the pre-set temperature is reach. Hope you find this helpful and good luck. Sam

 

[Michelle1972]

Yes thanks Sam, you've been most helpful ....now to find a honest and reliable plumber locally!!

 

[REDSAW]

see the wire at the front?.
there is a overide lever bellow it, press down then across it will then change the mode to heating and water.

i had one for years as i couldnt be bothered to fix it.lol.

 

[P/Boro Plumber]

Not to be recommended REDSAW, as this lever is to manually open the valve for venting and filling purposes only, if it is left in the open position with the heating running there is no control over the hot water temperature and the water cylinder temperature will just keep rising, possibly to a dangerous level. Please do not use this lever with the heating system running. SM


NO LINKS PLEASE

 

[dboi78]

i know it may be a little obvious but as i cannot see it previously mentioned check the cylinder stats setting and position as this may have a bearing on the little heat u are receiving other than that the gents are more than likely correct about the motorised valve......

 

[plumbandplumber]

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??

Its there for occasions like this. Boilers and other components break down. Until they can be fixed, the immersion heater will get you some hot water.

 

[Michelle1972]

Thanks to everyone for their help....although on checking water this morning it was hot?? Probablt best to get it checked over though yes?

 

[Michelle1972]

Hmmmm no idea if I am being ripped off......I apparently have sludge in my system as the pipework around 3 components in my airing cupboard are now magenetic and copper pipes are not? I need new pump, airator and diverter valve....slightly modify the pipework in the cupboard as its not very accessible and labour.....£345......does this sound correct guys? Oh and if I8 wanted the system flushing it would be another £275 on top

 

[Amir Akhtar]

Hmmm

Im not charging enough!

I would get couple of quotes luv.

 

[Gray0689]

Hmmm

Im not charging enough!

I would get couple of quotes luv.

Agree with this

 

[SafeGasInstall]

Cheap , go for it !!!

 

[Michelle1972]

I cannot afford to get the system flushed too so will changing the parts work? How do I know I actually need and that all the system just needs is a flush through?

 

[SafeGasInstall]

if you don't flush you will end up with same problem in less then 3 mounts ! do as plumber recommend to you !

 

[raymondo68]

If £345.00 includes VAT then it is probably fair, however be sure that you get some guarrantees. You are not buying a pump and valves, you are buying a solution to the problem. Some strategies for finding a good local plumber.... Gas safe register, trust a trader?? 2 websites that will give you access to local qualified guys.
Good luck

raymondo

 

[Michelle1972]

Its £345 for cash no VAT. This includes the 3 parts, labour @ £60 ph and the slight modification of the pipework in airing cupboard, plus £275 if I want the system flushing....He's coming tomorrow

How do I know what wattage (8,9 or 10) my shower is as I believe I need a new one? And how long to fit and price please?

 

[SafeGasInstall]

Michelle you said you can not afford flush , and now you are on about new shower ????

 

[Michelle1972]

New shower is approx £70 it can't be much more to install?? I can't afford to have it done yet I just need to know which one to buy and installation price

 

[kay-jay]

a 70 quid shower will be crap!

spend more and get a decent one


KJ

 

[Michelle1972]

which one will I need 8,9,10 watt....how do I know which to get....someone??

 

[raymondo68]

Hi Michelle

Like a lot of things it just not so simple to say which one. The difference between these showers is the flow rate that they will allow and still provide water at a decent temperature, the higher the rating the more water you will get. However, the bigger showers 10Kw will require a 10mm cable to be run back to the main fuse board if one is not already there.

The wiring regulations surrounding the installation of an electric shower are quite onerous.

To find out what you already have you could contact the manufacturer, or look for their website. Post the details here and someone may be able to help.

It is strongly advised to get a competent electrician to look at the existing cabling, they would then be able to tell you the biggest shower you can have.

Good luck

Raymondo