Unvented cylinder in living room

[nilsm]

Hi there,

we're looking to upgrade our hot water system [with the ultimate aim of improving our upstairs shower].

A plumber came round and suggested we replace our existing hot water cylinder with an unvented cylinder. The cylinder is installed in an airing cupboard in the living room. The plan seems to be to run the emergency outlet for the unvented cylinder along the skirting board and out to the balcony.

A neighbour told us that it's illegal to run the outlet in this way. Are they right? Or does the plumber know what he's doing? (he seems very knowledgable generally).

Cheers - Nils

 

[Duran]

Not sure on how your balcony is situated, but you can discharge onto a flat roof without a gutter - if that's what the plumber was getting at.

 

[AWheating]

the discharge must meet the building regs (part g3) it can not terminate in an unsafe location, onto a roof that cant take the temps, into a pipe or gutter that cant take the temps, onto a surface that could freeze and cause a risk etc....... i would think a balcony floor is not suitable unless into a drain.

 

[nilsm]

Thank you for your input! That's good to know about the balcony (there is no flat roof).

I take it there are no problems routing the actual discharge pipe around the skirting board, where it would be in plain view?

I would never have thought it would be quite so complicated to get a decent shower in our flat

 

[AWheating]

for me it would need a covering like a skirt boxing to stop it being touched when 100 degree hot water was flowing down it. and to make it look better.
it also needs to have a fall so it could no be routed level.

 

[kirkgas]

Re the discharge going onto the balcony, think about the scenario of many litres of very hot water being discharged quickly onto the balcony, where would it go? Some balconies have a small,drain to let surface water and cleaning water get away, however it's unlikely this would get the water away quick enough from the cylinder so there's a chance of a pool of very hot water being there, too dangerous, other balconies are flat and the surface water runs off the edge, so,again think of many litres of near boiling water running over the edge of the balcony to below, again too dangerous

 

[nilsm]

Thanks for everybody's input, this does not sound like a feasible idea anymore, it's been really helpful to hear your perspectives.

 

[Plumbstar Tom]

I would like to know more about the upstairs shower? what's the problem with it?

Could a correctly installed shower pump be a better and cheaper solution?

 

[Gray0689]

Have you considered an indirect thermal store? This would provide your mains pressure hot water without having to go to quite the same lengths for the discharge pipework. They can be manufactured as a rectangular unit to fit perfectly in your cupboard, meaning they take up less space and doesn't take up all the cupboard space.

You will be offering to sell him one soon I guess

 

[lame plumber]

decent plumber would also lift few boards and hide a blow off pipe

 

[markfxy]

decent plumber would also lift few boards and hide a blow off pipe

how do you get onto the balcony if you put it under the floor?

 

[Gray0689]

Only trying to give a solution to the problem, one of our products will do this yes but that is besides the point. Tell you what when people are offering advice don't start posting stupid comments...just a thought.

Just a thought be honest who you are
If you want to push your products become a sponsor

 

[iiplumbing]

Hi Nilsm

Where is your nearest waste or soil pipe?

Russ

 

[nilsm]

Morning all - all advice is welcome and I think I'm able to judge each on their own merit

To answer a few questions:

The problem with the upstairs shower: When we originally installed it 3 years ago the water pressure was low, so we went with a mains-fed low-power electric shower. It seems that silt or dirt in the pipes may have clogged it up - it just stopped working reliably pretty quickly. Usually very hot or very cold and recently after a water cut just stopped working altogether. We always thought it was low water pressure but that's just been checked and is actually pretty high. It's a maisonette with interesting plumbing - the bathroom is upstairs, shower has a cold water mains feed but sink + separate bath are fed from what we think is a communal tank with low pressure. There is a small cold water tank in the upstairs bedroom feeding the hot water cylinder downstairs in the living room. The whole thing is powered by a gas boiler in the front hallway.

Option 1 that was suggested was to put a 12watt shower in (currently 7.5 I think) + a filter to stop the dirt clogging it. That's cheap(ish) and quick but we've had a bad shower for the last 10 years and don't want to end up with just a slight improvement. Even the camp site we visited recently had a much better shower

I understand a pump is out as its not a tank-fed system. So options came down to unvented cylinder or combi boiler. Unvented cylinder has the issues discussed above. Our neighbours actually have a combi boiler so that seems like the sensible solution.

The nearest waste pipe to the hot water tank is in the kitchen, roughly same distance as balcony.

Thanks for input + lively debate!

 

[iiplumbing]

Hi Nilsm

If you can get a fall going from the intended location of the cylinder to the waste pipe in the kitchen then run the PRV discharge to the waste pipe

You have various choices

PRV - Tundish - some sort of non return valve - then in 22mm to waste pipe

PRV - Tundish - Hepvo reducer - Hepvo non return device then in 32mm to waste pipe

PRV - Hotun - in 22mm to waste pipe

Just some thoughts

Russ

 

[nilsm]

Just a quick note - thanks for everybody's input, it was helpful in reaching the final decision. We had a combi boiler put in and it's worked wonders.

 

[cypher007]

the discharge must meet the building regs (part g3) it can not terminate in an unsafe location, onto a roof that cant take the temps, into a pipe or gutter that cant take the temps, onto a surface that could freeze and cause a risk etc....... i would think a balcony floor is not suitable unless into a drain.

sorry to dig this thread up again, but im slightly worried about where my tundish terminates.

the G3 installer took it through the outside wall into a 90 bend and straight down into the conservatory guttering hopper. my thought after reading this comment was, would the plastic guttering/down pipe take the sort of heat?

 

[Mike Jackson]

No, shouldn't terminate into a plastic gutter. If you read the manual, which he should have left you, it will tell you.

 

[chris watkins]

No, shouldn't terminate into a plastic gutter. If you read the manual, which he should have left you, it will tell you.

Unless it runs for a suggested 3 Metres to allow cooling then it is OK.

The reality is cypher007 that although not the greatest install (should not have been done like that) the risks are small. Very very very rarely does a T&P safety valve discharge on temperature & secondly the plastic rain water pipe may well survive, if a little distorted, by the intermittent shots of hot then cold water.

Then you have to ask the question what damage would occur if it did, what else could be damaged & that includes people as well as structure.

Most times it just is not worth altering, just carry on living with the risk.