hi Corylus, still having problems i see!
(he says the air vent on the collector was installed incorrectly, parallel to the roof instead of being vertical) correct.
...
see this info it should tell you everything about the valve (A.A.V.) cheers

Thanks robbo

I'm looking at 5026 Yes?

And you are saying that it is correct that the valve must be installed vertically? What exactly happens inside it if it isn't? Remember I'm a little old lady and not a plumber, so be gentle.

It must surely be screwed into the manifold which has to lie at the same angle as the roof. So if the caleffi valve is screwed in at right angles to the manifold, it ain't going to be vertical huh? It is going to be parallel to the other side of the roof - which it is. There's nothing in the specs diagrams about where the air vent is fitted so I don't know what it looks like. Is there a bend of some sort to accommodate it so it can be vertical? Maybe the kit came without that bit. I'm finding it hard to believe that the plumber who put it in could have made such a mistake - he seemed to know what he was doing. The installer/owner/operator is something else altogether.

Hi Badger. I hope life is treating you more kindly? I kept up with developments but not in the last week, being somewhat involved with my own problems. I thought I had it sussed, but my Master Plumber won't play. Which I understand completely. But I do need some sort of authoritative back up if I am to go to tribunal. Right now I just want the damn thing removed and my money back.

So if you were given a kit with a panel of vacuum tubes and a Caleffi air vent, you would know you needed to braise an appropriate elbow to ensure the air vent was vertical? What about the screw threads at either end? (don't laugh!! or rather feel free. I don't mind ) Or should the kit come with an already threaded extension which you can then bend as required?

Cheers

Thanks for that integrated. I think I understand that but a photo would be good if you can find it.

I take it there is general agreement that this thing needs to be vertical. But I'm a right one for knowing why. Maybe you noticed    Who can tell me? Preferably translated into English - or even Physics. And don't say because it won't work if you don't. If I'm driven to take this guy to the cleaners I need to know I can win. So I'd like to be able to blind them with plumb. I don't imagine a referee on a tribunal will be an expert in plumbing but you never know.

Thanks guys.

corylus, if you want the meat for the referee to chew on, find the brand name of the aav and get the installation specs. end of storey.
but. bits falling out of the cylinder??? that's not going to happen.
bits melting ?
I don't see how the aav will do that.
if your system over heats the control module has failed.
here is what would happen......
aav fails.....system cavitates  ....circulating pump cant move water from the panels down to the hot water cylinder.
senor in the panel senses over heating.
system shuts off.

Thanks everybody. Bowtieboy first. What you describe in your first reply is exactly what happens. The circuit between the bottom of the tank and the collector develops bubbles and I have to bleed the pump to keep the circuit going so I can get some hot water. Bear in mind that I have it in correction mode these days with the pressure down as far as it will go and the cold water turned right off at the 5 way valve. Regarding damage to the wiring/melting/cylinder - this was due to the tremendous shuddering that occurred because the system couldn't vent through the air vent. The HWC would be at 85° and the collector at 120° and steam bubbles were coming back down and into the HWC creating ructions. As I recall, the pump was still running. I honestly thought the HWC was going to burst out of its restraints. It was quite terrifying. What else would break the wire in the cable so that it sparked and burned itself out but an earthquake size shaking? And I couldn't get the installer to believe me. I'll attach the sound bite again in case you missed it last time. And that's only half of it. I missed the shrieking sound because my husband had put the hot tap on while I was firing up the Mac. Sensor in panel senses overheating and shuts off ? The controller never shuts the pump off these days. Not even when the sun goes down mate. It is totally stuffed now.

 I have actually written to a contact at Caleffi and am waiting a reply.

Jaxcat. Thankyou. The master plumber came out of the kindness of his heart to see if he could help. He came 40km to do that and didn't charge a cent. I could not possibly expect him to get involved and I appreciate the fact that he came the way he did, in his own time, at his own expense. Regarding the installer - yes, I have been trying for months to get him to take responsibility for this installation. Years in fact. The overheating occurred within the first couple of months, as soon as the summer got into its stride (2010). I told him that it wasn't venting and he simply did not believe it. We live in a rural situation and he was never here to see it in action. It is him I have the beef with. He employed the plumber - not me. I thought they were a team. And I thought his business was a franchise, not a little small town business with the same name as the original one in Nelson. I still haven't figured that one out. To be fair, he does come and try to help, but I suspect he just doesn't have a grasp of the physics involved as a result of which he can't solve the problem and goes for finding a way to deal with the results of it instead - which can be downright dangerous. As in the present case. He wasn't able to work out the complexities of what seems to be a partial vacuum resulting from the pump being unable to access water from the bottom of the tank ( for some as yet undiscovered reason) , but just so I can get some hot water he wants to stick a valve in the header pipe - which is the only way steam has ever been able to get out at all. I didn't fancy having a bomb sitting in my airing cupboard waiting for the first hot day to go off, so I wouldn't let him do it./ I don't think our original plumber is a shyster at all. He's a decent man and I don't want trouble for him. But it has to be said - if that air vent isn't vertical, he's the one who did it. But he'd have put it right if he'd been given the chance - years ago. But because the installer never believed the vent wasn't working, he wasn't told. I'm not going to have the plumber crucified at this point years later, after all the subsequent damage has been done by not having it fixed. We all make mistakes, He'd have put it right if he'd known.

I trust there is a temperature/ pressure relief valve in the system?