Central Heating Component ID?

[Nigel Percy]

Hi,

Right all you knowledgeable persons. I moved house and am trying to get to
know
the various bits & pieces. What is the arrowed component in the following
picture

http://www.btinternet.com/~nigel.percy/heating.jpg

What's it for? How does it work?

Cheers

Nige

 

[Tony Collins]

Looks like an automatic bleed valve to me (lets air out of the system)

 

[Tony Collins]

It has a float in it which drops when air fills the bottle, opening up the
valve, and letting air out.

 

[Andy Hall]

Hi,

Right all you knowledgeable persons. I moved house and am trying to get to
know
the various bits & pieces. What is the arrowed component in the following
picture

http://www.btinternet.com/~nigel.percy/heating.jpg

What's it for? How does it work?

Cheers

Nige

It's an automatic air vent. There is a high point in the pipework
where it's fitted which would otherwise accumulate air.

Inside the brass chamber, there is a little plastic float, normally
with a lever with a rubber disc on the end. The disc covers a hole
in the top of the chamber, which in this case has a second cover on
the outside - the red cap. Air will tend to go up the vertical pipe
and to the chamber and the float will drop, opening the hole. Thus
the air escapes, water rises as does the float and the hole is closed.

These valves are not always perfect in sealing, so the red cap is
there as a means to prevent escape of water that is not known about.
You can check if there is accumulated air by turning the red cap
anticlockwise. You may get a few drops of water as the valve closes
if there is accumulated air.



..andy

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[geoff]

Hi,

Right all you knowledgeable persons. I moved house and am trying to get to
know
the various bits & pieces. What is the arrowed component in the following
picture

http://www.btinternet.com/~nigel.percy/heating.jpg

Looks like an automatic bleed valve to me - it has a float chamber
inside

 

[jackA]

Looks like an automatic bleed valve to me - it has a float chamber
inside

How effective are these ? I've got one fitted but a small amount of air
still manages to collect in the bathroom radiator every couple of months
during winter.

 

[Andy Hall]

How effective are these ? I've got one fitted but a small amount of air
still manages to collect in the bathroom radiator every couple of months
during winter.

They are reasonably, but can tend to weep after a while. Fixing
involves taking them apart and cleaning. On the better quality ones
like the Honeywell you can rotate the base and isolate the chamber -
then the top can be taken off for cleaning. On some of the cheaper
ones there is an auxilliary valve in the bottom which closes as the
chamber is removed. I 've had some of the Honeywell ones for over
a year and they have been OK so far and not seeped water. However, I
don't expect there to be much accumulated air either.

In any case this isn't necessarily going to help much with your
radiator problem, since the AAV will only trap passing air to where it
is fitted.

Have you checked that this is not hydrogen from your radiator? If it
is then you have a corrosion problem.




..andy

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