Another cold radiator

[13adl1x]

Hello,

I've replaced a radiator in the ground floor lounge as the existing one was to small to actually warm the room up. (checked using BTU calcultors and the amount of jumpers I was wearing!)

I have bled the system and there is no air in the new radiator, all the other radiators are hot but the new one is only warm at the top.

Any chance it is sludge from elsewhere in the system or is my pump to small or something else?

 

[Lagerkhan]

Air lock in rad.......guaranteed

Try turning off all rad valves except that one and the pump might move it.

 

[13adl1x]

So basically turn all the rad's off except the new one? I'll try that tonight.

JUst out of interest where will the airlock go?
I.e. does this just move it elsewhere in the system.

Do I have to bleed the new rad once all the others are turned off?

 

[ChrisR]

The air isn't in the rad, or the rad would be cold at the top.
It's in the pipes.
Once it's in a rad you can vent it.

 

[Lagerkhan]

JUst out of interest where will the airlock go?
I.e. does this just move it elsewhere in the system.

Do I have to bleed the new rad once all the others are turned off?

It might move it to anywhere in the system so you will have to bleed rads again. some may bleed itself depending on your system.
shut off all rads except that one.

 

[13adl1x]

Of course, kind of realised after posting that was a stupid question.

 

[13adl1x]

Hello tried shutting them all down except the cold one and it hasn't made much difference.

The only point I forgot to add is that the old rad was contacted to 10mm pipes, in total i replaced about 2 foot of the 10mm with 15mm pipe.

Would this make any difference?

 

[werewolf]

Has one of the rad valves got a drain off?
May be able to " drag" air lock out of pipes through it.

 

[Lagerkhan]

Hello tried shutting them all down except the cold one and it hasn't made much difference.
quote]

OK......This is what i would do !

Shut off both rad valves and undo nuts nearest to rad. drain rad into bowl and remove rad.
Then open one valve into bowl or through hose until air has come through and then do same with other valve.
refit rad and bleed.

 

[13adl1x]

Should I turn the heating off first or can I just leave it on obviously making sure that I top the pressure up?

 

[WelshMan]

Turn heating off whenever your bleeding rads or in this case removing them, that's all your doing is heating water and throwing it away expense to yourself.