Cold radiators...

[stevie1969]

Hi all,

Since I have moved into my house 3 months ago, 2 radiators downstairs were very slow to heat (sometimes not at all). We have open plan, so downstairs was very cold and i fitted a new radiator in the living area, fed via bedroom directly above. Downstairs is now toasting with only this one!

BUT, the other two radiators are not working properly. As far as I can see, as all pipes are hidden, the first radiator from the boiler is in the utility room (which is working properly) and the second is one of the rooms upstairs (all upstairs are also working)and then it returns back downstairs to feed the two that are slow to heat. Is the problem related to the upstairs then downstairs set-up?

I have shut off all radiators upstairs and they are still slow to heat downstairs

On investigation I found that the bathroom radiator supply and return have been crossed. There is an isolating ball valve on the feed and a TRV on the return.

So, is it one or the other problem, or a combination of both?

 

[xr4x4]

If you've closed all the hot rads and the other rads are still cold, have you tried opening the locksheids a little more?

Do they have trv's?

Also what speeds the pump on?

 

[stevie1969]

If you've closed all the hot rads and the other rads are still cold, have you tried opening the locksheids a little more?

Do they have trv's?

Also what speeds the pump on?

I have tried the lock shields open a little through to open full.

They all have brand new TRVs today.

I'm not sure of the pump speed.

 

[xr4x4]

With the system off, try running some water from both ends of the rad into a bucket, to check for supply.

Have checked the system is pressurised and or the feed tank is full?

When you draw off water from the rads, the level should drop in the tank.

 

[stevie1969]

Thanks, for all suggestions, it'll have to wait 'til I'm now - at work for two weeks. I'll let you know how it goes....

 

[stevie1969]

With the system off, try running some water from both ends of the rad into a bucket, to check for supply.

Have checked the system is pressurised and or the feed tank is full?

When you draw off water from the rads, the level should drop in the tank.

The radiators I have the problems with are Living Room 1, 2 and 3; "New Living Room" is the one I fitted myself, although I'm not quite sure that this is exactly where I have tapped from.

I have drained, removed and washed through Living Room 1 and 2 - neither seemed to be full of sludge, only some black water once I tipped it up. I have flow from both the supply and return with the radiators removed.
I then turned off all other radiators and restarted the system.Rad 1 gets warmer on the back half than on the front section and radiator 2 only get lukewarm. Radiator 3 was the same as 2. I put on all the other radiators and 1 and 2 are not as warm and 3 is cold (although pipe is warm up to the TRV)

All pipework is either hidden under the floor or boxed in skirting, so before I start dismantling my whole house, does anyone have any ideas?

I have also turned the pump up a wee bit, no difference.

I can run new pipes from the Utility Room to radiator 1 and block off the pipes coming from upstairs without too much intrusive work, would this solve my problem?


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[xr4x4]

Is this a one pipe system?

 

[stevie1969]

Is this a one pipe system?

Sorry, no, only a bad drawing! I only wanted to show the order of the radiators.
I've added the return line and the dotted line in the bedroom is where i think the loop may be breaking down.

Is it possible the return leg is going back to the boiler before servicing "living room 1, 2 and 3"?

I have also thought that I should maybe take the feed directly to rad 3 rather than 1, re-piping all 3 in 15mm. But, would this cause a similar problem with "new living room"(which is piped using 15mm)?


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