leaking auto air vent

[dboi78]

i understand that a leaking air vent in a combi is a sign that the expansion vessel is undercharged or split, but im not sure why exactly, is it just under a higher pressure than designed for so causes a leak, or is it something else ??

many thanks.

 

[Simon F]

if you mean the schrader valve on the expansion vessel is leaking water, then the membrane in the vessel is burst.
a high pressure will cause the pressure relief valve to open, typically 3 bar
if the auto air vent is leaking water it needs changing

 

[dboi78]

no i didn't mean schrader valve mate, i was watching the mr combi dvd a while back and he said that a leaking aav is a sign that the expansion vessel is gone, just wondered why that may be ?

 

[SimonG]

Not necessarily. All it's a definite sign of is that the aav is knackered or full of muck.

 

[aggis]

Just change the aav & while the boiler's drained check the exp vessel & repressurize if necessary.
If unable to get pressure into it, it'll need changing.

 

[dancinplumba]

need to be gsr to do the above imho

 

[Billy Bob Bob]

a leaking aav in a combi is not ​a indication the expansion vessels on the way out,its a indication aav,s not well just replace it

 

[Billy Bob Bob]

need to be gsr to do the above imho

only if its in the combustion box,a capable plumber could change it if its on the pump

 

[dancinplumba]

what about removing front cover ? ids that ok ?

 

[Billy Bob Bob]

read my previous post

 

[dancinplumba]

will takre that as read

 

[dancinplumba]

the op is to lazy to do it himself gman he carnt even be bothered to find out how much it costs to be gs registered

 

[Billy Bob Bob]

the op is to lazy to do it himself gman he carnt even be bothered to find out how much it costs to be gs registered

he wont get far in this trade then

 

[GrahamM]

no i didn't mean schrader valve mate, i was watching the mr combi dvd a while back and he said that a leaking aav is a sign that the expansion vessel is gone, just wondered why that may be ?

As far as I am aware most AAV's are rated upto 10 bar. So a 3 bar max pressurised system is not going to over exert an AAV.
As mentioned a dirty system may cause premature failure.

 

[Puddle]

Think he is just getting aav mixed up with prv

 

[Billy Bob Bob]

Think he is just getting aav mixed up with prv

yes probably cant see a mr combi dvd saying that,though not ever seen it

 

[Puddle]

yes probably cant see a mr combi dvd saying that,though not ever seen it

I lead a sheltered life,never seen a Mr Combi dvd,seen Goodbye Mr Chips and a few of the Mr Men adventures though and if he is as good as them,he must be a ok bloke :sailor:

 

[goz666]

I know a lad who regularly works in combi repairs, hes got his acs but isn't registered with gs. When he took the acs he enquired about the regs round working on combis to be told that anyone can work on any combi apart from touching or changing any gas carrying parts. I dont agree and have told him so, but he tells me thats straight from the mouth of his acs auditor???

 

[dboi78]

yes probably cant see a mr combi dvd saying that,though not ever seen it

He definitely said it and it was the automatic air bottle as he called it which I know to be the aav, I could look at the DVD again but I'm too lazy !!

 

[dboi78]

the op is to lazy to do it himself gman he carnt even be bothered to find out how much it costs to be gs registered

Where do u get off calling me lazy based on a post I wrote and never having met me ? I'm a 33 yo father of two that's worked full time in a variety of jobs since the day I left school, never claimed benefits never been on the sick, studied 4 hours a day to pass my acs whilst working full time......... Lazy ! I wish I had time to be lazy

 

[GrahamM]

A leaking AAV is not a sign your ex vessel is goosed. A leaking AAV is a sign your AAV is goosed!
A leaking/blowing off PRV is a sign your ex vessel may require attention.

 

[aggis]

My comment was if you've got the boiler drained you might as well check the Exp Vessel, just good practice & saves a call back

 

[mountainman]

I can't believe so many posts about a leaking AAV, change the ruddy thing and put it and us out of our misery!!!

 

[SafeGasInstall]

Where do u get off calling me lazy based on a post I wrote and never having met me ? I'm a 33 yo father of two that's worked full time in a variety of jobs since the day I left school, never claimed benefits never been on the sick, studied 4 hours a day to pass my acs whilst working full time......... Lazy ! I wish I had time to be lazy

dancinplumba I know dany in person ..... you owe him a apology you know !

 

[dancinplumba]

dancinplumba I know dany in person ..... you owe him a apology you know !

you are right, my sincere apologies dboi78