Hot water tank

[watchmefly]

Hi I’m having a problem with my hot water tank and hope someone might be able to help?

I live in a new build town house and have been here less than a year. The hot water tank makes a loud continuous hissing sound when the central heating is on, and there have been a series of loud ‘banging’ sounds which I assume is the (plastic) pipes vibrating, together with a low humming sound. The tank is on the top floor and the wall directly underneath it that forms the staircase wall was really hot this evening, as hot as a just boiled kettle and I couldn’t comfortably keep my hand on the wall for any length of time. The area that was hot was around 50cm in diameter. It did cool down later.

The plumbers employed by the developers are frankly useless, the one that came to look at it just shrugged his shoulders and effectively said ‘dunno’. I’m going to escalate this but just wondered if anyone had an idea of what the problem might be, I’m especially concerned about the hotspot on the wall.

Thank you.

it's a cylinder, not a tank.

It's unvented and runs at pressure. A person qualified to work on it must have passed an exam and have a "G3" certificate. Some heating engineers have it. if you can't find anyone qualified locally, the manufacturer's probably have a service network.

I think yours is one of these
www.kingspan.com/gb/en-gb/products/hot-water-cylinders/unvented-hot-water-cylinders/tribune-he-pre-plumbed-indirect-cylinders

Shows how limited my understanding is when I don’t even know the difference between a water tank and cylinder 😂

Good point about contacting the manufacturer about a properly qualified heating engineer and how to check, thank you.

Is it normal for a wall next to a hot water cylinder to get so hot?

no. It might mean there is an uninsulated pipe inside the wall, which is perhaps a bit shoddy but not really a problem. This is more likely if it is a hollow plasterboard wall.

Observe the white plastic cup thing to the right hand side. Water should not run into this unless something is wrong.

An unvented cylinder should be checked about once a year, find a person who is qualified to service your boiler and work on unvented cylinders and can do both on a single visit. They very rarely go wrong but it's not impossible, and are under pressure so the safety devices need to be checked.

Working correctly they can give you unsurpassed hot water.