Ah, ah - UK back in the space race..
Unvented Cylinder Vs Tradiotnal Vented - Did I Do This All Wrong?
- Thread starter JackK
- Start date
Ah, ah - UK back in the space race..
Sponsored Links
I saw one the other day knob builder had fitted boiler fix valves into the t+p valve and combination valve ( so that's both the cylinder safeties taken out if some diyer turns them of thinking he's isolating the water or the nuisance dripping out the discharge.
2 port valves fail all the time in open position. All you then have is the boiler high limit stat..
2 port valves fail all the time in open position. All you then have is the boiler high limit stat..
You might have a look at the OPs other post "Stuart Turner Noise - Is this normal" and make a recommendation.
Really - not even with a direct/indirect cylinder with a faulty runaway immersion heater?
Chances/odds are extremely low but not 0, never say never with these things IMO.
Sponsored Links
- Joined
- 30 Dec 2021
- Messages
- 10,518
- Reaction score
- 1,709
- Country
My general rules are fit pump onto a pathing slab (stone). If the floor is not level I'll even out with foam or some sort of cushion.
Never bend the hoses.
Pull bends on the copper Rather than using 90d elbows. And follow the manufacturers MI's
A hot water cylinder exploded in a house in Broxbourne just before Christmas 2020, a lot of structural damage including the roof.
- Joined
- 31 Mar 2013
- Messages
- 501
- Reaction score
- 47
- Country
You need multiple failures, so if your immersion ran over, the temp+pressure relief valve would vent the tank.
Usually when one blows up, it's because someone has willingly bypassed one or more safety features.
On another note, some new builds have these as standard, but there are new rules on energy box ticking where new builds have to have combi boilers, basically no stored hot water, which sounds like a step backwards to me.
The fact that there is always a chance that it can happen, even in a domestic setting, is the reason for at least 4 safety features, so there are multiple layers to minimise the risk. To say it wouldn't happen, especially on a DIY forum, isn't the correct information for some that may not know any better and then act unwittingly and incorrectly.
- Joined
- 31 Mar 2013
- Messages
- 501
- Reaction score
- 47
- Country
I didn't say it couldn't happen, what I said was, that is is unlikely to happen without intervention of safety devices, hence the UV cylinder isn't inherently dangerous, much like a gas boiler, but tamper with it and it may well become unsafe, with consequences.
Why does it fly upwards?
And (as per the video) why does a cylinder, that doesn't seem to have any water or power supply blow up in the first place?
In no way am I discounting the dangers but, instinctively, I would expect the middle of the cylinder to expand first.
I do not understand why a cylinder that is (ordinarily) side fed would fly upwards. Why wouldn't it explode sideways. To fly upwards, would, in my mind, suggests that the lower part of the cylinder is, a bit pants, ie the weakest point of the cylinder.
I could be wrong though....
The concave base is forced outwards into a convex shape which rips itself away from the cylinder as can be seen in the slow motion at the end of the video.
Some poor pictures of the hot water cylinder explosion in Wormley
www.hertfordshirebc.co.uk
Hot Water Cylinder Explosion | Hbc
HBC attended an explosion of a pressurised hot water cylinder, just before Christmas. It caused a huge amount of destruction internally!
www.hertfordshirebc.co.uk
- Joined
- 16 Oct 2021
- Messages
- 663
- Reaction score
- 71
- Country
just replace the lot with a continuos water heater and begin living in the 21st century lol. Silly how we still try and emulate the way of the Romans did it
You can't drop that statement without some supporting link to the source?
Fossil fuel boilers in new builds are going to be banned, we know, and heat pumps can't do instant hot water. So hot water tank storage will be essential in the not too distant future (2025?) if the UK is trying to save energy. But even that has still to come into law / the building regulations.
Having watched the YouTube video at 0.25 speed on my 4K laptop screen, I seem to see something different to you.
Let's assume that the top and bottom of the cylinder are "attached" to the cylinder using similar construction methods, ie, it is a tube with a top and bottom fitted, and let us also assume that the lids and base are the weakest points. Why would the bottom fail before the top? If the top failed, it would be a copper lid (alone) that hits the ceiling above (and lots of water spraying up and, invariably outwards).
Sorry, I don't understand why the underside- exclusively, will fail and not the top or sides.
I am willing to suggest that the video is not (possibly) completely truthful.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
