Capping off mains water supply in Loft

[darrude]

The house we are in has a very high mains pressure (7.5bar).

We have a disconnected Steam generator in the loft (there when we moved in), which at the moment can not be isolated. I want to take it out ASAP as it has started to leak (luckily not causing any damage at the moment).

It is fed from 15mm copper.

What are peoples thoughts on the most reliable type of end cap? Access is ok.. ish.

Many Thanks,

Darren.

 

[darrude]

Me Again,

didn't want to put a massive first post but more details....


I was going to put a compression fit end cap on there, but thought I'd get a second opinion. My other thought was to put a compression isolation valve on, then an then an end cap on the end of this (my theory that the force on the fitting would be less as the bore diameter will be smaller).

Long term plan is to find the feed into the loft and cap it off at source. We have boxing in the hallway where the pipe comes up which I suspect this is where the main feed splits to the bathrooms under the floor (it's a long time since my engineering apprenticeship and I only covered the basics, but I'm sure you aren't supposed to have long runs of capped pipes in case it breeds listeria, or is this just for hot water?)

Longer story, when we had the hot water tank moved I asked the plumber to remove and isolate it but he really didn't want to go near it. I have a mate the has just qualified (left army), he said he'd sort it but when I asked he just said he'd cut the pipe and put a JG speed fit on the end and didn't feel comfortable soldering a joint in the loft (it not in the eves, but admittedly I wouldn't be comfortable soldering there.

I'm happy to pay someone as if it goes wrong I can't imagine the damage it would do, but ideally want to sort it this week so I can sleep a bit better at night (water isolated at the moment), and talking like a drip every hour when the water is back on. I'm away with work till Wednesday so it will be getting capped off then, either by me or a plumber!

 

[Newboy]

you aren't supposed to have long runs of capped pipes

Correct - deadlegs need to be removed. Trace the pipework back to it's nearest active branch and cap there.
A 15 mm compression or pushfit stop end is the easiest fitting to use. If you go with a pushfit then make sure that the pipe is cut and prepared properly to ensure that there are no burrs to damage the 'o' ring.

my theory that the force on the fitting would be less as the bore diameter will be smaller

This won't reduce the pressure and will add two additional joints into your pipework.

 

[Hugh Jaleak]

Compression would be my choice in a loft, if there's a risk of it freezing, then plastic will split before brass. As above though, it needs tracing and capping at the tee, dead legs aren't allowed for reasons of bacteria forming, (thinks Legionella is more of a concern than Listeria, but either are not wanted!), so technically there shouldn't be anything in the pipe to freeze.

 

[darrude]

Thanks guys. Compression fit it is then... I thought about the isolation idea afterwards and realised I was a bit thick!

And a nice big hole in the wall next free weekend... Anyone want to tell my wife for me....

Thanks Darren

 

[Madrab]

TBH I would be soldering it, if the dynamic pressure is that high.

As long as safety procedures are observed, common sense prevails and access and lighting is good and clear then it's just as dangerous as soldering under a wooden floor and joists with insulation IMO, done it for years.

 

[durhamplumber]

The house we are in has a very high mains pressure (7.5bar).

We have a disconnected Steam generator

Unusual set up ...I am no expert but 7.5 bar dynamic pressure seems very very high in a house .. To the point every joint would be at risk of popping.

 

[dilalio]

I'd be looking to fit a pressure reducing valve on the main to get that down.

 

[darrude]

I'd be looking to fit a pressure reducing valve on the main to get that down.

That is a very good idea actually, we had a flood shortly after moving in as a water filter burst open, also had a tap pop off, and the replacement tap, only a year old is already starting to leak.

Thank you, I'm going to do that.

 

[darrude]

Unusual set up ...I am no expert but 7.5 bar dynamic pressure seems very very high in a house .. To the point every joint would be at risk of popping.

We get a higher flow out of the hose pipe than the pressure washer. Even the the plumber that tested was shocked. Definitely going to reduce it down as suggested.

It's very hilly where we live, our last house had high pressure, with a Yorkshire water owned reducer outside our property and an additional one inside. We are now on a road of only 2 houses. So guess we just get what we get!

 

[durhamplumber]

We get a higher flow out of the hose pipe than the pressure washer. Even the the plumber that tested was shocked. Definitely going to reduce it down as suggested.

It's very hilly where we live, our last house had high pressure, with a Yorkshire water owned reducer outside our property and an additional one inside. We are now on a road of only 2 houses. So guess we just get what we get!

Do wonder what the static pressure reaches during the night!

 

[darrude]

Enough to do this!