Gledhill unvented water cylinder leaking anti-vacuum valve?

[shambly]

I have a gledhill accolade unvented water cylinder.

Outside on the drive where the tundrill discharge pipe exits the house is often damp - no water is dripping past the tundrill but vapour is condensing down the clear plastic pipe from the anti-vacuum value (The end of this pipe sits below the tundrill in the tundrill pipe). The anti-vacuum valve is fitted immediately after the hot water outlet of the cylinder to the taps.

My neighbours identical system is behaving in the same way (damp patch on drive)

Is this considered normal? Does the valve need cleaning (crusty limescale) / replacing or the tank bubble recharging?


Thanks in advance

Simon

 

[shambly]

I've now read elsewhere that the valve is there to prevent a vacuum if demand for water exceeds cold supply - therefore, am I correct to conclude that the valve is faulty as its releasing water vapour?

Thanks

 

[oilman]

Excuse me while I just get on my horse, are you aware that you cannot work on an unvented cylinder unless you are a registered operator? The reason is these things can demolish buildings if they go wrong. Sorry, I'll get of my horse now.

 

[shambly]

Yes I am perfectly aware and have no intention on performing work on it.

I am simply trying to ascertain whether the valve is faulty or this is normal behaviour. I.e. Do i need to track down a (hard to find) qualified professional to get this fixed?????

Where is the harm in that???

 

[oilman]

There's no harm in that. But I see quite a few of these that are put in by non registered operators, and many don't get looked again for years. As they can cause such havoc, I just felt I had to get in the saddle again. I wasn't trying to be rude, it just comes across like that.

I would think for a definitive reply , an email to Gledhill would be a good move.

 

[shambly]

Oilman,

Thanks for the reply - I appreciate the time you (and the many others) spend here helping DIYers.

Any tips on making sure the heating engineer I choose isn't a bad 'un?

I've found 1 local corgi registered and 2 local IoP registered individuals.
How do I find out if they are truely competant to work on unvented water cylinder?

Thanks

Simon

 

[oilman]

How do I find out if they are truely competant to work on unvented water cylinder?

Wish I knew. Most of us are bad judges of character most of the time. (If you think you're good you'll be a) dissapointed or b) happy as a pig in sh**) If you feel comfortable that's probably the best you can do. If you don't feel comfortable, he may still be ok but your relationship will be strained which won't make either of you happy. The legal requirement is they must be registered and should be able to show you a card with their photo on it and a registration number. But that only indicates they admit to having been told what they should do, and have signed a piece of paper to that effect. Most tradesmen are ok, I don't like the young cocky ones, and the ones who won't answer questions. If you ask questions of course, you have to be honorable enough to give him the work if he answers them, and not just steal his knowledge.

 

[Potterton Man]

If my memory serves me correctly you don’t have a anti vacuum valve are you sure you are not talking about a temperature combined pressure relief valve these can often be re set by the customer and most have instructions on side of Tank

 

[shambly]

Potterton Man,

No, its not the P&T relief valve. The valve that is dripping is first in the flow path of hot water out to the taps out from the cylinder, at the top of the tank.

My accolade plus manual shows an annotated diagram of the sealed heating/mains pressure hot-water system, (and my system is laid out exactly as per the manual) so I have identified all of the components.