Megaflo auto air valve leaking again

[Lloydy77]

Hi,

I noticed some months ago that my Megaflo auto air valve was leaking so I replaced it, the replacement valve has also started to leak with a waxy residue. I recall that the original AAV had a black lid and the replacement has a brass lid, does it matter which version is fitted? Can I permanently remove the AAV and bleed the system elsewhere?

 

[Chuck]

What brand is it and is it specced correctly for your heating system? Pegler Prestex ones have a five year warranty IIRC. OTOH, if it's a knock off from eBay you get what you pay for.

IME, this type of AAV has never been noted for reliability. If they're not in an easily monitored position it's a good idea to fit them with an isolating valve so you can leave them working for a few days/weeks after draining and refilling, etc. and then shut them off for the other 99% of the time that they are not needed.

 

[John.g]

The condition of the system water maybe should be looked at as well, I prefer the manual "thumbscrew" type air vent that can be opened occasionally.

 

[Ben-gee]

If your cylinder is heated by solar thermal you need a specific aav that is rated above 100 deg C, a “normal” one will fail very quickly .