Megaflow: what is this?

[deglanh]

Got a very small lead from the cap of the part in the picture below. It's part of the maze of plumbing for my home megaflow. Does anyone know what this part is called or what it does?

[Draxindustries1]

Pressure relief valve..

[littlebasher]

Looks like an auto bleeder.

I'm sure a plumber will be along shortly with the correct answer !

[Lincsls1]

littlebasher said:

Looks like an auto bleeder.

I'm sure a plumber will be along shortly with the correct answer !

That is correct, it is an AAV - auto air vent.

[Justin85]

An automatic air vent. Lets air out of the heating system. It looks to also have a nut in the bottom you can undo - there may well be a filter or strainer in there to catch debris in the water.

When they fail they let a little bit of water out of the vent on the top, as you know!

[deglanh]

Thanks everyone.

[anonymous-user]

As above. It’s a deaerator.

[anonymous-user]

MDMA . said:

As above. It’s a deaerator.

It's most likely a deaerator - which isn't quite the same as an automatic air valve. A deaerator includes a wire mesh element which actively promotes the formation of air bubbles for expulsion.

[Lincsls1]

Either way, the section that is leaking is the AAV portion which looks and should be replaceable without disturbing the whole body.
A bet the top piece screws into the main body and is the same as another common AAV fitted as standard to loads of boilers and systems.

[Lincsls1]

For example...
https://www.google.co.uk/shopping/product/14734983...la,productchannel:local,storename:4589,product_id:446436&lsft=gclid:EAIaIQobChMIm92GnJmI_AIVFY3ICh22kgBKEAQYCiABEgKcgPD_BwE,gclsrc:aw.ds&sfr=compass