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.

 

[joni os]

Converting a single bungalow to a 5 bed house is hardly a massive construction project, although I accept it might take an extended period of time if frustrated by neighbours calling in HSE and being pedantic over party wall surveys. The definition of commercial work was given by poster. For some people the definition of what constitutes an emergency depends on whether it's their neighbours central heating or their own that has broken down.

 

[Radioman]

Converting a single bungalow to a 5 bed house is hardly a massive construction project, although I accept it might take an extended period of time if frustrated by neighbours calling in HSE and being pedantic over party wall surveys. The definition of commercial work was given by poster. For some people the definition of what constitutes an emergency depends on whether it's their neighbours central heating or their own that has broken down.

I am really going to have to bite my tongue now. Obviously you have never been in the situation where your privacy, property, equilibrium, have been threatened. Anyway, thanks to the Norman Conquest and Magna Carta we have ruling classes that made the rules to protect private property.

Obviously that is all said with tongue in cheek. Hope you are put in the position of having someone try to build on your land, or an absentee landlord who refuses to maintain his property and boundary. ( party wall act etc)

 

[kay-jay]

I personally always fit a gate or lever valve on the hot outlet on an unvented cylinder.
It most certainly is not illegal and it also is most certainly not going to cause the cylinder to implode, quite the opposite in fact.

I fit them for 2 reasons.
1) it is an immediate shut off
2) if you are only working on the hot supply in future, the cold supply to the house remains uninterrupted for the duration.

 

[kay-jay]

The other advantage of fitting a gate or lever valve to the hot water outlet of an unvented cylinder is ....
If you have this dedicated hw shut off and you operate it. You can check hw outlets around the property. Any water out the hot tap instantly diagnoses a shower/mixer tap fault

 

[Sparkgap]

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.

Unvented HWS 101: :smile5:
Sounds like one plumber is a bit old skool remembering the days of tank fed cylinders when the HWS outlet also acted as vent/expansion and it was a big no-no to shut them off.
Assuming the cylinder has been installed correctly any expansion should be taken up by either the internal air cushion or an external expansion vessel on the cold feed and any protective devices such as cut-outs, safety valves or temperature/pressure relief valves should be on/in the cylinder and not isolatable by a carelessly fitted valve! Therefore there should be no issues with putting a valve on the hot water outlet to isolate your mansion and the plumber who says otherwise is either totally misinformed or conversing out of his rectal orifice. 🙂

 

[macackau]

I am G3 registered and when I installed my own unvented cylinder and customers I always put a pressure guage, pipe thermometer and full bore lever valve on the hot outlet from the tank. The guages help with checking everything is working as it should be and the full bore valve makes isolating the hot water very quick and easy.

 

[dancinplumba]

Unvented HWS 101: :smile5:
Sounds like one plumber is a bit old skool remembering the days of tank fed cylinders when the HWS outlet also acted as vent/expansion and it was a big no-no to shut them off.
Assuming the cylinder has been installed correctly any expansion should be taken up by either the internal air cushion or an external expansion vessel on the cold feed and any protective devices such as cut-outs, safety valves or temperature/pressure relief valves should be on/in the cylinder and not isolatable by a carelessly fitted valve! Therefore there should be no issues with putting a valve on the hot water outlet to isolate your mansion and the plumber who says otherwise is either totally misinformed or conversing out of his rectal orifice. 🙂

could you say that again please