Radiators are hot but the heating is not on

dantheman2010

It was a bit difficult to try the things suggested when I didnt get in until gone midnight and then out for work again at 7am this morning. As I said I will try later.

chrisw

Mine went a couple of weeks ago similarly. I found that if I turned off the power to the system and then turned it back on again, I could hear the valve moving and then it was ok for another day or so.

I found it easier in the end to replace the whole valve which meant draining the system down but took about half an hour excluding draining and filling time.

My advice is to get it done now. Otherwise you can guarantee it will fail completely over christmas like mine did 10 years ago and that was no fun at all.

dantheman2010

I definitely dont want it all going wrong over the winter period - I take it that if it is letting in water to the heating pipe when the hot water on it could fail all together and perhaps not open either at all?

My plan is to give the lever a little wiggle just incase it has got a little stuck, if this has no joy and in the morning it heats up still then I am going to get the multimeter tomorrow, check the motor (I presume the hot water/heating needs to be on to test this)? If the motor is gone then I am happy to replace that and do it myself, if the motor is fine then I will come back on here for a little more advice - if it turns out it may be the whole valve then I will get a like for like replacement for £85/90 ish but will need a plumber to drain down the system as I dont have a clue on how to do this UNLESS someone can direct me. Will report back what happens with the wiggle and/or multimeter results.

Thanks guys.

DVardysShadow

dantheman2010 wrote: »

Hi all

Wondering if someone can help.

I have just noticed that my bathroom and spare room radiators are both warm/hot even though the heating is not on. None of the other radiators in the house are hot, just these two.

The hot water is on so I am not sure if that has anything to do with it. I have now turned both thermostats on the radiators to off, but some of the others are set to 3 or 4 and as I say are not hot.

I dont get it? I had the one in the bathroom replaced at Christmas but not the one in the spare room.

I havent noticed them or the rooms they are in being hot whatsoever.

Any ideas?

Thanks

There is one other scenario which has not been mentioned here, it is mentioned somewhere in some versions of the instructions for the Honeywell divertor valve.

This arises from a minor plumbing error. If the returns for more than 1 radiator are connected in the run of return from the HW cylinder to the boiler, it is possible to get a flow of return water the wrong way up on radiator and back the right way down the other.

I raise this because there are 2 radiators involved and it appears that some plumbing work has been done recently.

dantheman2010

Thanks for this, so what would this require? Yes the only two radiators that were heating up were the ones that the plumber worked on in December (brand new rad in bathroom and new TRV in spare room).

DVardysShadow

First of all, you need to understand the problem for yourself and then you need to be able to explain it to your plumber and get him back in to sort the problem.

• If you are lucky, he will understand and fix it
• If you are unlucky, you will need to explain the problem
• If you are very unlucky, he will try to ignore you even if tell him how to fix it

Basically, if you look at the return pipe to the boiler, and follow it back from the boiler, the first connection you encounter into the pipe should be return from the HW cylinder, rather than the returns from the 2 radiators.

chrisw

As above, you really need to understand how your system operates otherwise it's a bit of a goose chase. I think when mine jammed in winter previously it was hot water but no heating.

I bought a brand new Honeywell valve off ebay for £30. The draining of mine was simple - turn the water off (I had an isolating vave before the ballcock in the loft tank so didn't need to turn the whole house off), put the little lever on the diverter valve onto manual which opens heating and hot water circuits (which is the point yours appears to be stuck at), connect a length of hose to a drain on one of the downstairs radiators valves and open the little square-ended valve so it drains out. If you open the upstairs air bleeds on the radiators it drains a bit better.

Refilling is a reversal and I added a bottle of rust inhibitor as it filled. Keep bleeding the radiators until there is no air left.

The wiring for the valve was easy, just a matter of replacing like for like. But make sure the power's off first!

dantheman2010

Thank you very much all.

Canucklehead

Hi,

Was pipework altered when the rad/s were fitted?

Try this................

Turn on your c/h.

On the two offending radiators note which pipe gets hot first.

Mark it with tape .

Tomorrow morning when the fault occurs note which end gets hot first.

GSR.

dantheman2010

Canucklehead wrote: »

Hi,

Was pipework altered when the rad/s were fitted?

The pipework was not altered when the rad was changed, he just took old one off and popped new one on.

Thanks for suggestion about noting which pipe heats up, will do that today. I wiggled the lever no joy. Bathroom rad heats up when boiler first fires up and once that stops firing it cools down and stays cool for the rest of the time the hot waters on, its just when the boiler first fires up when it switches on.

So I will turn heating on it a little while and see whats what with the pipes, then I will borrow a multimeter and check motor.

Thanks