Auto air vent check valve?

[Friday round]

Hello. The auto air vent above my unvented indirect cylinder’s primary return pipe has slow drip that starts and stops after heating up the water. Suspect it’s due to debris. Searching on the forum, the advice seems to be to replace the part. I searched online for like part and it seems to be sold with a check valve, for such reason. For example: https://www.bes.co.uk/automatic-air-bottle-vent-1-2-with-check-valve-7704/

Question is does the one I have include a check valve? Is it below the line indicated?

 

[denso13]

Not that I can see, looks to be straight on to a female adapter.

 

[Madrab]

I assume it closes when the bottle is removed from the fitting. Yours looks like a normal one tho.

 

[Friday round]

Thanks all. Will be adding this to the DiyNot list then.

 

[muggles]

It's a brave man who relies on one of those check valves to seal properly when replacing an AAV anyway. If the AAV isn't sealing properly due to dirt, it's unlikely the check valve will either

 

[Friday round]

Just giving an update. Didn’t replace the AAV (yet). Found some YouTube suggestions for diagnosing. Gave it some soft knocks to loosen any debris, check fluids filter was clean. Checked the pump, setting and it was set to 3 so reduced it to 2, and bled the pump valve. Seems good so far. Don’t know why pump was set to 3 in the first place. I guess I’ll eventually find out.