By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

Central heating woes.

All Topics | Latest Posts

Search for:  in Thread Title in  
Robin Graham19/04/2020 23:52:23
709 forum posts
167 photos

Our heating/hot water went down a couple of weeks ago - low pressure, so the boiler shut down. I repressurised, no problem, it happens from time to time. But then it happened again a week later, the gauge was down to zero. This time I noticed water dripping from the boiler. So clearly a leak in its innards.

British Gas (I have their Homecare policy) refused to come out as it isn't an emergency - we can still get hot water and heat by repressurising and coping with the leak. At what point it becomes an emergency I don't know. Perhaps when the leak gets so bad that it destroys the boiler electronics and/or forces me to shut water off at the mains.

A question to anyone who understands plumbing though.

I've got everything going except the kitchen radiator, which remains stubbornly cold, despite my having bled it and every other radiator in the house. Not a life-threatening problem, but annoying.

Any advice?


Brian Sweeting20/04/2020 00:12:57
419 forum posts
1 photos

If it has a thermostatic valve on it try taking the head off and seeing if the valve pin is stuck.

If it is stuck down you can, very carefully, try lifting it with a pair of pliers. Don't pull too hard or it might come out and produce a small fountain.

not done it yet20/04/2020 07:44:29
4648 forum posts
16 photos

Perhaps when the leak gets so bad that it destroys the boiler electronics and/or forces me to shut water off at the mains.

Expensive, but not necessarily an emergency. Isolate from mains? Surely the system has an isolating valve, or valves? So there should be no emergency in having to close off the whole supply to the dwelling? Just make sure the fault is reported to BG, in writing, so they are made aware that any further damage to the boiler should be covered by their scheme. Also, ask their advice on further action by you to prevent any further damage which could be caused by them not attending.

Do you not have an immersion heater in your hot water system? I would not want a system whereby there is no alternative when the inevitable occurs (it packs up).

Johnboy2520/04/2020 07:45:22
259 forum posts
3 photos

I’d second the explanation that Brian has given. 👍

Werner Schleidt20/04/2020 07:51:45
97 forum posts
146 photos

Hello Robin,

after the water pressure goes down the radiator has now air in it. Therefore no heating is possible.

You have to let the air out of the radiator until water comes again. And then you have to look to the system pressure and add water to the central unit again.

I have sometimes the same problem in my kitchen.



Edited By Werner Schleidt on 20/04/2020 07:52:17

Nicholas Farr20/04/2020 08:28:40
2264 forum posts
1099 photos

Hi Robin, as Brian has said, a thermostatic radiator valve can get stuck down sometimes. I have had it happen to one of mine, and very often it can be cured by closing the valve right down and then opening it again or just tapping the valve body with a rubber mallet.

Regards Nick.

Maurice Taylor20/04/2020 08:28:46
86 forum posts
9 photos

I would take cover off boiler to see if I could see leak ,might only be a joint needs tightening.

You could put a bottle of Fernox leak sealer in the system ,usually stops most leaks.

blowlamp20/04/2020 09:13:42
1346 forum posts
84 photos

Cancel your 'Homecare' policy before you do anything else.

Bob Brown 120/04/2020 09:35:41
1010 forum posts
127 photos

I'd be inclined to investigate just where the leak is, it could be something like the diverter valve if it's a combi boiler.

Once the location of the leak is identified and the faulty part found, you should be able to order the part online. Then get a few tools out and replace it having drained down the boiler first.

There are many videos on line that show how to replace parts so not that difficult to do and before there is the outcry of gas safe, it's not a gas issue just water side.



Edited By Bob Brown 1 on 20/04/2020 09:37:19

Peter Layfield20/04/2020 09:43:02
33 forum posts

I would find the leak first, and then repair, -- joint leak or boiler and replace or as Maurice suggests radweld or other make of water sealant and then repressurise and bleed radiators

Bob Brown 120/04/2020 09:51:25
1010 forum posts
127 photos

Rad sealer will not work where parts move like diverter valves.

mark smith 2020/04/2020 10:42:50
671 forum posts
331 photos

Youve probably got an air lock or build up of sludge somewhere. But ours isnt a closed system. I went through the whole circus of cleaning out our radiators manually one by one using hose pipes to clean out all the radiators ,taking each off and carrying outside. I did leave cleaner in for several day before i started. It has actually worked ,we already had a power flush years ago and didnt want to pay for another one .

It even solved the problem of the valve sticking and not switching off when the timer went off.

My parents combi boiler is always leaking, british gas usually come out and often just tighten one of the brss nuts under neath it.

Graham Meek20/04/2020 11:13:14
215 forum posts
151 photos

My Daughter had a leak coming from the inside of her boiler. It had been leaking for sometime as the scale deposit on the gland nut showed. This had been missed by 3 service engineers. A quarter of a turn with a spanner stopped the leak completely. I could access the nut from beneath the cupboard in which it was installed. Might be worth a look as the symptoms are the same as my Son-in-law was experiencing.



Dave Halford20/04/2020 14:14:03
750 forum posts
6 photos

Diverter valves are a known leak issue

Bob Brown 120/04/2020 14:27:29
1010 forum posts
127 photos
Posted by Dave Halford on 20/04/2020 14:14:03:

Diverter valves are a known leak issue


As I found out when it tripped the RCBO on the boiler feed with water in the motor.


Edited By Bob Brown 1 on 20/04/2020 14:28:00

Harry Wilkes20/04/2020 15:29:27
895 forum posts
61 photos
Posted by blowlamp on 20/04/2020 09:13:42:

Cancel your 'Homecare' policy before you do anything else.

I'd be inclinded to keep it at moment just in case something else happens etc then you can always say your fault it got worse because you failed to come out !


Robin Graham21/04/2020 00:05:12
709 forum posts
167 photos

Thanks for replies.

We haven't got thermostatic radiator valves, so that's not it. Just 'taps' on one end of the rads and lock shields on the other.

It's strange that only one radiator is affected. It must be an airlock or perhaps a solid blockage. Maybe I should try kicking it - but that's Lockdown Psychosis speaking.

Probably I should cancel Homecare, but, as Harry says, now may not be the moment.


Samsaranda21/04/2020 00:15:56
930 forum posts
5 photos

It’s worth checking for any loose unions, at our previous house we had a new boiler fitted and the heating engineer asked if we had smelt any fumes from the old boiler he had removed, we had always complained of a smell of gas and he said not surprising as the gas inlet pipe Union was only finger tight, the system was serviced annually by British Gas, needless to say we don’t use them anymore.
Dave W

Mike Poole21/04/2020 07:21:07
2575 forum posts
60 photos

My boiler has an automatic air bleed which after 24 years had decided to leak, now I tightened the cap it doesn’t leak or auto bleed any more, ought to sort that out I suppose.


Jim Young 221/04/2020 15:14:40
20 forum posts
5 photos

Could I suggest closing the valves (not the lock shield end) of all the other rads in the house. This should cause a gurgle and air to move. It is possible on some pumps to turn up the flow rate (small slider or dial) note original position and return to this setting as overpumping causes it’s own set of issues in due course?

Make sure lock shield valve of affected rad is fully open for the ‘blast through’ and returned to original setting once complete ( count number of turns that you move it).

Be aware that shutting the valves on the other rads may cause them to weep ( especially when cold) you may need to nip up the gland packing nut on the spindle.

Hope you succeed !

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
Eccentric July 5 2018
Allendale Electronics
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest