New rads causing issues - inc. picture of layout

[TheCat13]

Hi,

I have just fitted 2 new rads to a conservatory off the main circuit. When I charged the system up, all worked well and they warmed up nicely. Its on a combi boiler and both rads have new TRV's

Now a day later they refuse to get warm. What are the possible solutions and causes. Airlock? The rest of the house is toastie warm.

Also, just a general question, I have heard a few people say a few rads will not get warm. I don't believe a powerflush is the answer as its been a more recent issue rather than a build up. I suspect a faulty TRV or blockage somewhere. Now the question is, lets say its a faulty or stuck normal wheel head valve, how do you determine that the valve is at fault or lets say there is a blockage in the pipe leading upto it somewhere. Obviously taking the valve off is an option but a drain down is necessary and its not guaranteed to be the problem. You could be replacing a perfectly good valve.

Thanks in advance Sam

 

[Diyisfun]

Im not a plumber, but have you tried to bleed them again?

 

[TheCat13]

Yes, they are full of water and excessive bleeding, brings a little hot water into them but does not seem to promote a circuit of water.

 

[TheCat13]

New rads in conservetory

• TheCat13
• 3 Dec 2008
• 1

Here is a schematic of the pipework I did. Is this right or should there be 2 separate runs for each rad. Or am I just being daft and there is just an air lock somewhere.

Thanks

 

[D_Hailsham]

Did you rebalance the system? Depending on where the new rads are in the circuit will determine what effect they have on the original balance.

 

[TheCat13]

Good question, I did not, is there a sticky on here regarding re-balancing or can you provide some guidance

Thanks

 

[D_Hailsham]

You can find info on balancing in the FAQs or I have given detailed instructions in other posts. See //www.diynot.com/forums/viewtopic.php?p=1068597#1068597

 

[TheCat13]

Thanks for that, the instructions seem really detailed.

From my description, does that sound like the problem. I have opened all the lockshields fully.

Does my circuit diagram look ok?

Once again, many thanks

Sam

 

[landyandy]

Hi.

Try turning off other rads, to force the two problem rads to get the supply.

And then balance the system.

Andy.

 

[D_Hailsham]

From my description, does that sound like the problem.

It's a possibility. However, your description of the radiators initially getting warm and, the next day, refusing to warm up, points to a possible blockage or airlock.

Shut all rads except one and check if that rad warms up OK. The do the same for all the rads in turn. This checks that each rad is basically working - water going into and out of the rad. If any rad stays cold, check the radiator valves. Failing that you will have to check for blockages.

I have opened all the lockshields fully.

Oh dear! that will disturb the balancing completely. Shut all lockshield valves and then open them a half turn. This will give a basic starting point for a quick balance. If you do not want to do an in-depth balance, feel the flow and return pipes at the boiler and then adjust the lockshield valve on each radiator until the difference is approximately the same. Only adjust the valve by an eighth turn or less and wait for the temperature to stabilize.

Does my circuit diagram look ok?

Nothing wrong with it.

 

[TheCat13]

Thanks. The main thing from my point of view is that the installation is ok. I intend to do a full balancing act! I have an infrared thermometer so should be able to do a good job and it will be great practice.

I will report back and let you know how I have gone on.

The Cat

 

[TheCat13]

Another very quick question.

If draining down a system, is it necessary to close both valves on a rad (to save draining it all and wasting inhibitor), or can I just close the TRV/wheelhead valve and leave the lockshield where it is.

Thanks again.

 

[gigz]

Yes you will have to close both valves, reading your post was the water in the system hot when you filled the new rads , thats why they worked at first.

 

[TheCat13]

Thanks again.

I do believe I charged the system with cold water first and then kicked the boiler into action. Does that change your view of the possible problem.

The Cat

 

[gigz]

If you turn off the other rads do these rads warm up ? if so, it souns like a balancing problem (see faq's)