rads not getting warm (have bled)

[yelf]

So the radiator in the kitchen gets slightly warm, and the rad in the lounge doesnt get warm at all. Al other rads are fine.

I had a plumber round 2 days ago (to fit a new thermostat for the boiler), and he looked at them, took off the TRVs, and said they had sticky valves. We turned off all other rads and they both got fully hot.

He said the system didnt need balancing.

But Now having turned all other rads on the same 2 dont heat up! Any ideas?

 

[PlumbBobBob]

your plumber was wrong, your system needs balancing.

 

[Deleted member 32524]

In brief. Close them all down, but one. (furthest from boiler) get heat in it by opening the other side valve from trv. Open in little turns till it heats. Then work your way to the boiler doing this.

Hey presto a balanced system.

 

[yelf]

In brief. Close them all down, but one. (furthest from boiler) get heat in it by opening the other side valve from trv. Open in little turns till it heats. Then work your way to the boiler doing this.

Hey presto a balanced system.

The rads that are cold are nearest the boiler. So you're saying the rads furthest away should have the lockshields open a little, and then the closer to the boiler I get the more they should be opened?

I read online that it should be the other way round??

 

[Simon F]

It's as Steve B said, the system DOES need balancing.
if the rads that are not heating up are closest to the boiler then it sounds like they are closed down too much on the lock shield.
but are they just closest to the boiler, or is the pipe run the shortest to the boiler?
the two are not necessarily the same.

 

[yelf]

Well the 2 rads are both in the part of the house that was extended, so would it make sense that they are actually furthest away?

 

[yelf]

I just checked and the lock shield valves on these 2 are both fully open, so I guess I need to slightly close the other ones. When I do what DuncanM says, should the TRVs be fully open?

 

[jtsplumbing]

If faulty rads are in the new extension it could be a problem with pipe size ! or you may need to fit a larger pump. but balancing may solve your problem.

 

[PlumbBobBob]

I just checked and the lock shield valves on these 2 are both fully open, so I guess I need to slightly close the other ones. When I do what DuncanM says, should the TRVs be fully open?

yes the trvs should be fully open, all the balancing should be done with the lock shield valves.

 

[yelf]

yes the trvs should be fully open, all the balancing should be done with the lock shield valves.

Ok, so i turned all lockshields off and TRVs fully open. Turned on the heating and starting with what i think was the furthest away rad, opened the lockshield abit til it got fully hot. Then went to the next rad etc. All this was fine until i got tothe last 2 (the 2 cold ones),: opened the lockshields fully and nothing!

Anymore thoughts on what it could be?

 

[PlumbBobBob]

just to make sure they work start with the two cold ones and work in reverse order. if after opening the next valve, the previous one goes cold open it up a bit more but not by much. the valves will pass full flow when open only a small amount so you don't need them "fully open"

 

[yelf]

just to make sure they work start with the two cold ones and work in reverse order. if after opening the next valve, the previous one goes cold open it up a bit more but not by much. the valves will pass full flow when open only a small amount so you don't need them "fully open"

Ok. I did that and all the rads got hot: of the two cold ones one got hot and one was bouncing. But the heating just came on and it was the same story, although they both received a bit of heat

 

[yelf]

This till isnt resolved. Weirdly, when the heating is on the water that comes pout of the down stairs kitchen tap gets hot for about 10 seconds then goes back to normal.