Auto Air Vent leaking and replacement.

[LeekBoy]

Hello this is my first post so if someone can help it's be great!

My boiler's Worcester 28i aav is letting water out. I noticed it as it caused the fuse to blow so I investigated.



Anyway I am going to replace it as soon as possible if I can. Can a standard bottle air vent be used, with a 1/2 or 3/8 inch thread?



My second point is, when draning the combi do I drain the whole system or just until the gauge reads 0. It'd prefer to do that as it will mean less re-filling time, etc. Should I close off the flowe and rrturn valves under the boiler or leave them open when draining as I have heard stories about this being a pain after being used?




Thanks for reading my 1st post everyone.

 

[Burnerman]

Depressurise your system until the gauge reads 0.
I use a fabric strap wrench to shift these...Machine Mart CHT245 - or if thats not man enough, CHT243.
John

 

[LeekBoy]

Thank you Burnerman.

Is draining it to 0 bar on the pressure gauge enough, as my boiler is downstairs. It won't pish out when removed May sound silly, but 0 bar means no water to boiler level (gauge level)??

Also, is a 1/2 male fitting the one or 3/8 the correct size? I should check the boiler manual I guess for this size..

 

[Burnerman]

Draining to 0 is fine - you'll just get a few drips after that.
Most WB stuff seems to be 1/2" and new AAV's come with an 'o' ring - but I only do oil stuff so I can't comment on your particular application.
John

 

[Boilerman2]

Does the AAV on your Worcester protude though the top casing? I know that some worcesters do, if this is the case with yours, you must order the correct replacement part from Worcester, as the vent must fitt snugly into the rubber bush to maintain the boiler case seal!!

 

[thefloosyonthebeach]

Thank you Burnerman.

Is draining it to 0 bar on the pressure gauge enough, as my boiler is downstairs. It won't pish out when removed May sound silly, but 0 bar means no water to boiler level (gauge level)??

Also, is a 1/2 male fitting the one or 3/8 the correct size? I should check the boiler manual I guess for this size..

Its a sealed system, a 'vacuum' will hold the water in. You will have only 1 'open end'. No air can get in so no water will pis s out as you delicately put it

You may need a worcester AAV (boilerman2 has explained it)

Model of boiler....? CDI? Then we can give you more accurate information.

Flooze