Problems with a new radiator

[Teggs]

Hi people,

I recently added a radiator in my lounge, following details I got off the net I drained down the system, cut into the pipework, and using a coil of plastic, rigged up a new radiator. I've filled the system and don't have any leaks (not bad going for me!).

I seem to have a problem though. The pipework where I junctioned off from the original system is quite hot, but the pipework leading to the new radiator is stone cold as is the radiator.

I'm not sure if I have overlooked something really simple, the valves are open and the pipework is clear. The pipework does not pass through any joists but does go over the top of a noggin that supports two joists. The pipe passes over it at a steady gradient and falls at a steady gradient. I’ve checked that I’ve connected the flow and return correctly and as far as I can see it is.

I've read about air lock but don’t understand the principle of it. Can anyone offer some advice?

Teggs.

 

[ollski]

you don't mention if you have bled the air from your rad and pipework.

 

[Teggs]

Sorry,

Yeah I've fully bled the system including the pump.

 

[CH4]

Have you tried turning off all your other radiators, to use the full force of the pump to shift any air that may be trapped in the pipework to the new radiator?

 

[MANDATE]

It looks as though your pipes going gradually up then down is the cause of your problem.
When you refill the system the water rises from the bottom to fill the pipes which will have left you with air trapped at the top of your new pipes.
The air cannot be pushed along like water because of the resistance and the fact it can be compressed.
If using the pump with the other rads. off don't work, you could try reducing the resistance.
With the radiator removed, secure a 1/2 in tap connector and a few inches of 15mm pipe to each valve in turn and run off a couple of bucketful of water.
I use two 1/2 in tap connectors and a few ins of 15mm pipe on each one and between the two I have 5ft of clear plastic tubing. With this I can clear the air locks and with both ends connected I can observe the water flowing through the tube before fitting the radiator