Unvented cylinder - advised it may explode

[Madrab]

They are at it IMO. They haven't addressed the issue why they were called out for and just defaulted to "you need a new cylinder". I'd be asking to see the chaps qualifications who came to look at the system and check he was actually qualified for unvented and solar as he needs to be to look and review that cylinder and it's setup.

Chances are all he did is send a pic to his boss, hence the comms. Water through the tundish doesn't make the system dangerous, all it means is one of the safety devices is active which is exactly what it's supposed to do but it does need looked at.

As suggested, if it hasn't been serviced then it needs to be by someone properly qualified in both UV cylinders and solar too, I would also suggest that if they are qualified for both of those then they will probably have the other experience/quals to look at the whole system and get it running correctly.

Was this a new build to you? If you've had nothing but problems then it should have been fixed under warranty.

 

[BigBadBarry]

Thanks everyone. Appreciate all your help and expertise. The cylinder is magnetic, therefore steel, as you stated. The 'corrosion' however, appears to me to be primarily a build-up of deposits on the outside, as opposed to rust. I can chip it off with my fingernail. I can't see where the pressure valve is seated because it's concealed behind a circular sticker, but I would assume it's brass screwing into brass, so not rusty.

It was new build to me, but lack of servicing is true and I don't expect to have a warranty, should I need to replace it. I think next step is to get a different firm out to assess it. I'm really tempted to refuse to pay the first guy - £100 for not fixing or diagnosing the original fault, then giving me a cock-and-bull story about exploding and taking the roof off. Really annoying.

 

[Madrab]

These cylinders, when everything goes wrong, can take the roof off the house but I don't think yours is anywhere near that.

The crusty build up will probably be limescale and that will start to rust the steel but again the bits below shouldn't be overly affected but can only guess as much not being on site. It needs a reliable and trustworthy professional to look at it and give an honest diagnosis, sadly they can sometimes be hard to find.

 

[gas112]

one problem that could occur with the cylinder if the fitting is brass . There is a thing called dezincification that occurs with water leaks and the brass just crumbles away .
The likelihood is cylinder will be ok but be prepared for renewal