Unvented Cylinder

[voicey]

A quick question: Do unvented cylinders need to be safety checked annually? I know qualified people have to fit them but do they need to be checked by law?

The reason I ask is that we rent and have an unvented cylinder. The water has become unbelievably hot as of late. So much so that to shower we have to have the the hot water on a trickle (and I mean a trickle) with the cold on full blast. Even then it's too hot! When we first moved in we used to have the hot fully open and the cold half open.

Thanks in advance.....

 

[HARALIAN]

A quick question: Do unvented cylinders need to be safety checked annually? I know qualified people have to fit them but do they need to be checked by law?

The reason I ask is that we rent and have an unvented cylinder. The water has become unbelievably hot as of late. So much so that to shower we have to have the the hot water on a trickle (and I mean a trickle) with the cold on full blast. Even then it's too hot! When we first moved in we used to have the hot fully open and the cold half open.

Thanks in advance.....

You need someone rather sharpish to check this out.They gotta have an unvented ticket.
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moderator

edited to correct quote

 

[Slugbabydotcom]

They should be checked annually according to manufacturers instructions and my best advice, don't think there is a law about it tho' someone else may be able to clarify that.
Sounds like you have a problem with a thermostat on the device that heats the cylinder [boiler or immersion heater] could need adjusting or renewing.
Is there any water running though the tun dish?
If what you are telling me only applies to a shower outlet there could be a thermostatic mixing valve faulty.
Don't mess about with it yourself as unvented cylinders are a different ball game to normal plumbing stuff

 

[voicey]

Don't worry I'm not gonna touch it. It's not just the shower but it was th ebest way to descirbe how the temp has increased.

What's the tun dish? It's electric immersion.

 

[oilman]

It's probably the thermostat. Not really a big deal, though relatively expensive. If you have two heaters, quick fix is to get the stat from the unused heater. As it is a rented property, don't do it, tell whoever and get them to sort it.

 

[ollski]

The tundish is the visible plastic break in the pressure relief pipe....reason being that your final safety device on the temperaure side is a temperature and pressure relief valve which will open and release water down the p.r. pipe.

 

[voicey]

Thanks for the responses guys. The tundish is unbroken so i guess it's not going to explode!

Both the immersions are switched on. I've switched one off to try and find out which one is giving the hassle. The bloody management company are useless and we are moving out this month anyways.

 

[Slugbabydotcom]

When Oilski said

The tundish is the visible plastic break in the pressure relief pipe

and you replied :-

The tundish is unbroken

He didnt mean that sort of broken

look inside the 'open' bit and see if you can see any water dripping through

Theres four lines of defence before it has the potential to explode and the immersion heater thermostat including reset button which should cut out before 90ºC are first and second
followed by the Temperature and Pressure Relief valve and an expansion valve.
Water running through or steam coming from the tundish indicates that the thermal cut out has failed and you are on your last lines of defence.
Unvented cylinders over 15 litres must be registered with the local authority planning dept. Perhaps they would be interested in helping you get on the landlords case a bit.
Sorry for scaring you here and this is scary but my point is that it needs sortin out.
Say a pressure cooker holds a litre of water and 6 litres of air and you could take the lid off it when it was at 143.5 ºC at 3 bar pressure thats 43.5 psi in car tyre terms could you imagine how well cooked and tender you would be when they scrape you off the wall. After say 200 litres of water at 2 -3 times that pressure has flashed to steam they wouldnt find the wall

 

[doitall]

Super Heated steam they call it, can get to 1500psi