Replacing Automatic Air Vent

[pgatsky]

I need to change the automatic air vent completely and wondered how I should go about this as I have just added inhibitor to the system so don't want to dump it all.

Someone I was speaking to recently said that if I drain the system down to that highest point I should be alright without having to drain the whole system down. To do this I presume I would need 2 people, one to look at the AAV and one to stop the drain off point?

Can anyone out there shed any light on this for me?

 

[ChrisR]

Depends on the aav and how high in the system it is.
If you close any other air inlet point (like another aav) and let the pressure off, you shouldn't lose water even if it's at the bottom.
Or if the aav has an auto change valve you're ok.

The hex bit at the bottom of this stays on the pipe. You can unscrew the aav

and screw a manual vent in

 

[pgatsky]

Thanks ChrisR

If I'm replacing a different make model to the original I'm not sure if the two will work together like you say.

I only have one AAV so what would be classed as another inlet point to close so I can let the pressure off?

I will try and upload a pic of the one I have so you can see.

 

[ChrisR]

If I'm replacing a different make model to the original I'm not sure if the two will work together like you say.They only come in two threads, 3/8" bsp or 1/2" bsp.

I only have one AAV so So you don't have another inlet point to close

so I can let the pressure off?
Use any convenient drain point

 

[pgatsky]

so I can let the pressure off?
Use any convenient drain point

Would the normal way of draining the system then be ok for this purpose? And for how long should this drain port be left open to let the pressure off?

 

[pgatsky]

Cheers ChrisR

Just a thought.

I am at home this afternoon and was in the bedroom when the HW just came on for tonight's baths etc. As the airing cuboard is in this room it allowed me to hear the problem again. I was always under the impression that it was happening when the CH was coming on, but I now think it's just when the HW actually comes on instead. Does this have a bearing upon this problem? It's the same problem, basically a sound of air/water rushing through the pump (or around that area) but like I say I think it may just be when the HW is coming on and not the CH as first thought.

Could it still be the AAV?

Any suggestions??