If you try bleeding a rad but nothing comes out...

[Londoner]

... what does it mean? No air, no water. I thought one or the other had to come out?

I was bleeding an upstairs rad because it was cold at the top but hot at the bottom, and I thought this was because of trapped air. I did this whilst the CH was on. Does anyone have any advice?

 

[ollski]

If your cold feed pipe is blocked nothing will come out as no water will able to enter the system.

 

[thanks in advance]

is bleed valve blocked with crud inside radiator.
i had similar problem.
turn off heating and hot water,electrically.
BEWARE...dont just try to see if it is blocked before turning off radiator at both ends.then protect walls and floor with old dustsheets,then take pin out,and use a strong needle to clear out any crud,be ready to put pin back in fast.dont panic.
failing that, 1.have you a presurised system ?.2.expansion tank ball valve seized closed. 3.any isolation valve between expansion tank and system connection,turned off. 4 worst situation is a blocked cold feed,where it enters system.
i have had all these faults in different houses i have had.

 

[Fluffster]

Is your system sealed?
If so and the pressure has dropped you will get nothing out until until you top it up.
pete

 

[Softus]

Does anyone have any advice?

My advice is to read this topic: before you ask a question please read this

...and then do what it says.

 

[pannierstan]

If its got a header tank in the loft check that the ballcock aint stuck before you start looking for blockages

Stan

 

[Londoner]

Thanks for all the tips.

I checked the tank in the loft and there was plenty of water. In the end, all I had to do was bleed it again but with the heating and hot water OFF. Air came out as expected and the radiator is fine now.

I was a bit thrown the first time when nothing came out at all - didn't think that was possible! Anyway, all good now.

 

[Fluffster]

Good stuff
You should always bleed any system with the pump/heat off as it may draw air intoithe system.
pete