Why do i need to bleed raidators all the time!?

Why do i need to bleed raidators all the time!?

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Discussion

philv

Original Poster:

3,911 posts

213 months

Sunday 28th November 2010
quotequote all
Hi,
I seem to need to bleed radiators quite often (usually the ones upstairs).
After a couple fo days ro so (i think) i again have trapped air.
I turn the central heating off before bleeding.
I bleed the ones upstairs last.
Anyone have any ideas?
This started before the cold snap set in recetly.
Thanks,
Phil.

alfaman

6,416 posts

233 months

Sunday 28th November 2010
quotequote all
I had this problem a while back.

..it transpired the central heating pump had been installed above the pipe rather than below it - air was getting trapped in the pump ; seemed to cause an issue with air getting into most radiators.

when the pump was replaced the problem has [largely] gone away.

[FYI : I am not a plumbing expert - this is just my own experience ]

Pints

18,444 posts

193 months

Sunday 28th November 2010
quotequote all
How do you know when your radiator needs bleeding?

Been in our place for 3 years and haven't bled a radiator yet. Whether I need to or not is another question.

number2

4,264 posts

186 months

Sunday 28th November 2010
quotequote all
Air gets trapped in them - near the top - and so they don't fully heat up.

sinizter

3,348 posts

185 months

Sunday 28th November 2010
quotequote all
Pints said:
How do you know when your radiator needs bleeding?

Been in our place for 3 years and haven't bled a radiator yet. Whether I need to or not is another question.
Probably when they stop getting as hot as they are supposed to. Atleast that's the rule I follow.

Pints

18,444 posts

193 months

Sunday 28th November 2010
quotequote all
sinizter said:
Pints said:
How do you know when your radiator needs bleeding?

Been in our place for 3 years and haven't bled a radiator yet. Whether I need to or not is another question.
Probably when they stop getting as hot as they are supposed to. Atleast that's the rule I follow.
Cheers. #Heads off to feel all of the radiators#

ferg

15,242 posts

256 months

Sunday 28th November 2010
quotequote all
It'll be:
Micro-leak on the pump suction side.
Sludge in the system forming hydrogen.
Pumping over pulling oxygenated water from the header tank.
Pump pulling air down the vent.
Pump pulling air into an auto air-vent when firing.

One of those.
smile

Lord Flasheart

125 posts

166 months

Sunday 28th November 2010
quotequote all
alfaman said:
I had this problem a while back.

..it transpired the central heating pump had been installed above the pipe rather than below it - air was getting trapped in the pump ; seemed to cause an issue with air getting into most radiators.

when the pump was replaced the problem has [largely] gone away.

[FYI : I am not a plumbing expert - this is just my own experience ]
Another possibility is you have a leaky pipe. Doesn't even have to be a big leak, an almost invisible pin prick could be enough to cause your problem. Do you find you need to keep re-pressurising the system?

Again, this is from previous experience. I'm not a plumber either.

Gingerbread Man

9,171 posts

212 months

Sunday 28th November 2010
quotequote all
I'm getting the impression that it's an open system with a header tank in the loft and not a sealed system where you top up the pressure via a filling loop?

If the latter then it won't be pulling air in through the vent. If you do have a vent, you could put your hand over it to see if it's sucking while the boiler is firing.

To check if it's hydrogen and not air, when bleeding a radiator, put a match near the gas coming out of the bleed vent. If it lights then it is hydrogen which would point at sludge deposits/ rust being the problem.