Shut off valve for hot water

[LCV]

Hi,

I've had a new heating system installed (system boiler and indirect unvented pressurised hot water cylinder) as part of a house renovation. I've had two plumbers in, plumber1 who is part of the loft conversion company and the plumber2 part of builder's team for the rest of the house.

When plumber1 was connecting loft to the heating system he said that he noticed there was no shut off valve for the hot water. As one was not there he said he had to wait 45mins for the hot water to drain and if I had a shut off valve then he wasn't have had to do that. As such he would recommend asking plumber2 to put one in above the hot water cylinder.

However when I approached plumber2 with this request he said it was illegal to add a shut off valve above the hot water cylinder and if he did so there is a rest it would explode as it is a pressurised system.

I am very confused as plumber1 seemed to be a very competent plumber so I doubt he would have advised doing something so dangerous. I wonder if plumber2 is just saying that because he doesn't want the hassle of adding it in or perhaps I have misunderstood what plumber1 was advising me to do.

Great to hear your thoughts on this.

 

[Jay The Plumber]

Im pretty confused by your post..

what does the hot water cylinder have to do with heating system ?
the way I read the post was that plumber 1 drained the domestic hot water to install heating in the loft ?

 

[PlumbBobBob]

it is usual to have an isolator, either gate valve or lever ball valve on the cold feed to the cylinder but not usually on the hot leaving the cylinder. is your cylinder open vented or unvented?

 

[Jay The Plumber]

he said the cylinder was unvented so yea, valve on cold feed.
its the "draining the hot water installing heating into a loft conversion" which is worrying.
hoping that OP has misunderstood both plumbers 🙂

 

[Riley]

Having a valve on the hot and cold pipework is no different to having a tap at an outlet???

 

[kris]

Pressurised system takes seconds to drain as, when you switch mains off your only draining wots in the pipe work, are you sure you haven't picked him up wrong, is he not on about draining your old tank to fit the new one??? Either way isolation valves are preferred on most pipe work situations,

 

[Rickster123]

Which of the two plumbers is g3 qualified? I'd be taking his advice only.

 

[Riley]

Which of the two plumbers is g3 qualified? I'd be taking his advice only.

Ooh the testing question

 

[chris watkins]

Not withstanding the above post.
It is possible to have a valve installed on the hot water outlet (normally out of the top of the cylinder) so long as all the safety valves & any expansion vessel connections are not interrupted.

It is not usual on most domestic systems as the hot water isolation is normally carried out by turning off the valve on the cold feed as others have said.
If you have a balanced cold water supply feeding the rest of the house & separate isolation of the hot & cold systems is required, then the isolation of just the hot can only be achieved by the insertion of a valve on the hot outlet.

 

[LCV]

Thank you very much for your replies.

Plumber1 had recommended putting in a full bore 22mm lever valve to shut off the hot water supply coming out of the unvented pressurised hot water cylinder.

Plumber1 was on site to do second fix in the loft ensuite and the radiators in the bedrooms. He said he turned off the cold water and when he went to look for the shut off valve for the hot water he couldn't find it. He said is it normal to have both. This caused him to have to wait 45mins for the water to drain.

He said if I ever had a problem and called out a plumber they would have to wait 45mins too and I would be paying for them to stand around which I obviously don't want to happen. But if I had a shut off valve above the hot water cylinder then it would be a simple case of turn off, cold and turn off hot and job done.

 

[LCV]

From reading your replies, it sounds like it is not standard to have a shut off valve above the hot water cylinder. Is it just not needed or not advisable to have one (because it is unsafe, illegal as the builder said).

I wonder why plumber1 said what he said?

 

[Jay The Plumber]

From reading your replies, it sounds like it is not standard to have a shut off valve above the hot water cylinder. Is it just not needed or not advisable to have one (because it is unsafe, illegal as the builder said).

I wonder why plumber1 said what he said?

hot water in your unvented tank is pressurised from the cold feed, turn it off and job done, no hot or cold water.

so shouldnt be a problem to do your connections for cold and DHW just by turning that off. no need to mess with that at all if you are fitting rads.

 

[plumben]

I'm struggling to see why he would need to drain the unvented tank to connect into the hot,
As soon as you turn the main off on a unvested system the water stops

 

[Old Account]

As above mentioned G3 qualified engineer would be preferred - no headache no pain afterwards

 

[Rickster123]

As above mentioned G3 qualified engineer would be preferred - no headache no pain afterwards

Not preferred, essential.

 

[LCV]

Unfortunately I don't get to choose the plumber. Plumber1 is part of the loft company's team. Plumber2 is part of the builder's team.

 

[ShaunCorbs]

aslong as there is a stop tape incoming to the cylinder (which there should be ) post a pic up of your cylinder and someone can point it out, your fine

and just for added piece of mind put some decent valves on before taps and toilets

 

[Rickster123]

Unfortunately I don't get to choose the plumber. Plumber1 is part of the loft company's team. Plumber2 is part of the builder's team.

So it's not your house they're working on??

 

[LCV]

It is my house but I have gone for the main contractor route which means they have their own team of people, i.e. builder, roofer, plumber, carpenter etc.

I am 100% happy that I have gone down this route and I would advise anyone doing a full house renovation to do the same. It would have been a complete nightmare, unless you are an experienced property developer, to hire all the individual trades yourself.

 

[LCV]

Thanks ShaunCorbs I will do that. The scale of the renovation means we don't live on site so I will take one tomorrow and will post.

 

[chris watkins]

LCV
Lets get this sorted the valve on the hot water outlet is not essential so don't have it fitted, by the sounds of it it would be an extra anyway.
If it proves that it is necessary then it can easily be cut in afterwards by a G3 plumber at low cost.

To all of you who have claimed that hot water taps stop instantly after you turn the cold feed off on an unvented system have not had the pleasure of draining too many Megaflo (bubble tops) where the bubble acts like an accumulator. I have had some that run for 10+mins if you only have a tap or two on.

 

[Best]

It is my house but I have gone for the main contractor route which means they have their own team of people, i.e. builder, roofer, plumber, carpenter etc.

I am 100% happy that I have gone down this route and I would advise anyone doing a full house renovation to do the same. It would have been a complete nightmare, unless you are an experienced property developer, to hire all the individual trades yourself.

No offence, but if you are really 100% happy with your choice of getting builders to do both stages, - then why do you need to come on the forum to ask which, if any of the two plumbers was correct? If you had a G3 plumber that knows about plumbing systems, then they would have done it properly and give you correct advice.
If you know a good tradesperson, - use them, but if you want to take the risk of using builders who bring unknown tradespeople, so that you can have less responsibility, then sometimes you will have problems.

 

[LCV]

Best - I came on the forum because I have two plumbers giving completely opposite advice. So I wanted to get other qualified, G3, plumber's views so that I can decide on how to proceed.
I don't know any good tradespersons so that's why it would have been a nightmare to find all the required people that I could trust that are available exactly when you would need them on site during the course of the 1 year renovation project and for them to not hold up any other tradesperson's job.
Hiring a main contractor does not mean I have less responsibility, it is about managing risk and who is responsible for when something goes wrong. If you ever decide to renovate your own home you will soon realise when there is a problem that tradesperson is going to be blaming someone else.

 

[LCV]

Thank you Chris, your reply has been very helpful and sorted out my problem of what to do.

Also your comment about the draining time makes sense and I think plumber1 is right then with his 45min estimate. The house is over 4 floors, there are four bathrooms, kitchen and utility room so lots of taps!

 

[Best]

It is irrelevant how big the house is really. The water comes from the unvented unit, which will stop usually quickly if the supply valve to it is turned off.
I understand you getting a builder in to take all the trades jobs. However, you are gambling if you do not know the tradespeople. Plumbing particularly is one trade that builders seem to use poor materials and workmanship.
The fact you have been given conflicting advice from the two plumbers shows that at least one of them is wrong.

 

[Jay The Plumber]

the biggest worry is the draining down of the PV, unneccesary and makes me worry that someone has connected DHW to rads (yes, I've see it)

 

[LCV]

I was careful in selecting the main contractor. It took me six months to find the right team. I was very diligent when my checks, I visited his previous clients, followed up on references, checked his insurance, reads reviews on various trade sites, he is a member of the FMB, trustmark, etc. This company specialises in full house renovations and it would be in my builder's interest (as he owns the business) that he employs, not sub-contract out, a good plumber as every house renovation involves plumbing.
Every renovation, especially your own home, is scary and carries risk. I am relieved to say that I have been happy with their work so far, they have sorted out problems with no hassle and have been good to work with. We are due to move back in two week's time.

I am baffled with why plumber1 gave me that advice and plumber2 said what he said (as I doubt very much it is illegal). Even on this forum I've received different views.

 

[Best]

To fit a lever valve on the hot outlet of an unvented unit by a G3 plumber is possible, but not usually needed.
A valve to the supply to the unit is obviously needed, but it is illegal and a potential safety risk to fit it in incorrect place.
I can't understand the plumbers not explaining it properly

 

[Radioman]

Unfortunately I don't get to choose the plumber. Plumber1 is part of the loft company's team. Plumber2 is part of the builder's team.

Basically you are perfectly within your rights to ask the contractor to confirm the qualifications of any of the tradesmen he employs. This is especially important for electrical and plumbing work. I am afraid in these days of open borders there are workers on many sites in the UK that are not qualified to practice their trades in the UK. Regulations for electrical and plumbing installations are not the same in any of the EU countries.

I am not suggesting that this is true of your contractor, we all know UK tradesmen are quite capable of corner cutting. But this is what can happen.

A neighbour of mine recently did exactly what you are doing: employed a company to knock down 85% of his 2 bed bungalow and build a 5 bed house. Carried out all due diligence, same as you. Turned out the company employed Lithuanian and Estonian trades exclusively. Not knowing any better and based on references etc he expected it to be a good job and generally it was. Except it was built to Eastern Europe regs, not UK. Building controls and health and safety had a field day. Electrics condemned , construction methods wrong, such as no brick ties, joists set into walls not on hangers, cavity wrong size, lintels installed without pads, insufficient protection at height, no public liability insurance, no safety equipment or protective clothing, working outside permitted hours, including Sunday's and Bank Holidays, everything like we would have done it in 1952. It was quite entertaining sitting in my garden listening to the arguments through a translator between building control, the foreman and the various trades. The recurring theme was "I don't care how how it's done at home, your not doing it like that here. Do it again"

Ultimately you are the one responsible for the final product. You are the one who will have to provide all the certificates for electrics, plumbing, Windows, etc, etc, if and when you sell. So simply asking the boss man to provide you with the installers G3 qualification should not be a problem, should it?

 

[joni os]

Don't understand above reference to:- "working outside permitted hours, including Sundays and bank holidays". Sounds like something people working 9 -5 would like to enforce, until the boiler breaks down on a Saturday night, or they need to visit A&E.

 

[Radioman]

Don't understand above reference to:- "working outside permitted hours, including Sundays and bank holidays". Sounds like something people working 9 -5 would like to enforce, until the boiler breaks down on a Saturday night, or they need to visit A&E.

Ok commercial building sites are required to stop operations after 13:00 Saturday's no work on Sunday's and Bank Holidays. No start before 07:30 and finish no later than 18:00. This includes quite works but not emergency work. This can be varied depending on planning permission and Party Wall Act contracts. 90 % of councils in England and Wales will enforce this if a complaint is received. There is an initial request to cease and if not complied with a section 60 prohibition notice is issued tout suite. Definition of Commercial is any works that are being paid for directly or indirectly. Basically it's there to protect the sanity of communities forced to endure noise and disruption caused by care less and usually Cowboy Builders, parking of trades vehicles and the usual pollution associated with construction.
If you had ever had to endure massive construction on your doorstep you would understand.

 

[joni os]

Being as I'm neither careless or a Cowboy Builder may explain why these restrictions are have never been applied to my works. Parking of a trade vehicle in a residential area is essential for most self employed plumbers. Sanity is something I'm not certified to comment on.

 

[Radioman]

Parking of a trade vehicle in a residential area is essential for most self employed plumbers.

Care less not careless. As in couldn't. Most sole traders park with consideration. And I was also referring to General Construction not single plumbers.

Personally I have sometimes had to park in the next road to the job and certainly in Greater London, would not move the vehicle again for fear of never getting anywhere near the job on return. We used to equip the vans with folding cycles for that reason. The particular reference I was making referred to a particular site that had 9 vans parked half on half off the pavement blocking both pedestrian and wide vehicles from passing.

 

[stevetheplumber]

i think joni is confusing small works with larger sitework .all work sites will have restrictions on when they can work its different to one man turning up for an hour to change taps were talking about jobs that may stretch over months and the disruption it may cause
bet you looked good on a folding bike with a bag of tools and two lengths of 4 inch radioman

 

[Radioman]

i think joni is confusing small works with larger sitework .all work sites will have restrictions on when they can work its different to one man turning up for an hour to change taps were talking about jobs that may stretch over months and the disruption it may cause
bet you looked good on a folding bike with a bag of tools and two lengths of 4 inch radioman

Ha ha LOL, they got used for popping to the shops for lunch or to the merchants for bits and bobs, tile trim etc. Small stuff. Cheaper than a mini cab though. Try parking in Hampstead or Crouch End.