Central heating problem

[Joel19]

Have had British Gas out 3 times to this problem.

One of my radiators just does not work. If I turn all the others off then it comes "Warm" but thats as good as it gets. As soon as I turn the others on it goes cold again and two other rads at best only get warm.

I have bled them all. The boiler is working fine. Its 2 years old and is serviced yearly. It's a Halstead Combi condensing boiler

On BG's recommendation I have had the system power flushed and its cost me nearly £700 ta very much and it's not made a blind bit of difference. The engineer informs me there are no blockages? Every engineer has told me something different and I am getting a bit fed up with it all. Any idea's as to what could be causing this problem???

(All of these problem rads are downstairs. The boilers is upstairs and the upstairs rads are fine)

 

[MikeyGas]

Have you had this problem since the boiler was installed? Did you have a conventional heating system before this, i.e tanks in the loft and a hot water cylinder?

 

[compheat]

I know this might sound daft but have you made sure that the isolation valves under the boiler are fully open I had a problem like this years ago and did everything i could think of to get the system working, and yes you've guessed it was the valves that were practically shut stopping the flow.

 

[Joel19]

The problem has occurred this winter and as for the valves as far as I am aware they are open? but I will check

 

[Registered Gas Man]

*edit*

 

[Nige F]

Replacement boiler 2 years ago ..System should have been powerflushed then British Gas know your home is your world They just know much more about making ££££. If they recommend "something" don`t they guarantee that what they do will have some result OR are they just Legalised eejits with a virtual monopoly. First off I`d look @ the rad valves ...take off and examine ...maybe one has broken off half closed ,or even got a lump of something jammed in it . Because if it`s always been restricted , what`s to say a "power" flush is powerful enough to shift it . You`ve had BG 3 times ...that must be their 3Star service

 

[MikeyGas]

Did BG "balance" your system after they powerflushed?

 

[Steady]

It sounds like you are going to need to take the offending rad(s) off the wall (after closing valves either end and draining it) and then open each valve in turn into a bucket and see what comes out. If you have a blockage at the valves this will give you an idea. Also worth hosing out the radiator in the garden and see if the powerflush left anything behind!