Water Mains Upgrade

[Shadoman]

Hi, would appreciate some help please. I've had a look at other posts and am left confused.
We are having an unvented cylinder installed in our garage. Currently we have a vented cylinder on 1st floor.
The property was extended on ground floor to the rear. When doing this, they buried the water main under screed and teed off above around and feed it to the garage and put a stopcock in the garage. This run from the ground to the garage is about 1-1.5m in 15mm.
All the gas/heating engineers I've spoken to said I have 3bar pressure (when tap is ruining) and about 20-22litres/min.
Off this 15mm. They think this is sufficient to feed the UV cylinder but recommended we run a new connection from the outside valve on the footpath.
I've had quotes for between £1600-1900 to do this. It's a 15m run to the garage.
My question is, should I live with the small section of 15mm which will be uprated to 22mm and connected to UV cylinder or bite the bullet and lay the new pipe. I'm not really sure if it's worth the money.
Any advice would be greatly appreciated.
Cheers

 

[Hot&Cold]

We are having an unvented cylinder installed in our garage.

Have you and your g3 installer discussed your needs and demands,you want a decent water system

 

[Shadoman]

We did, yes. Why do you ask?

 

[John D v2.0]

All the gas/heating engineers I've spoken to said I have 3bar pressure (when tap is ruining) and about 20-22litres/min.

That's an excellent flow with great residual pressure, presumably that is after the run of 15mm you're concerned about?
If so I wouldn't bother digging anything up, just run the pipes after that in 22. How many showers do you want at a time?

 

[Shadoman]

Hi John D, this is what I thought and was advised by the installers. You are correct, it's after the 15mm so they are planning to come off there at 22mm and into the cylinder. We will run 2 showers simultaneously, on occasion. No baths and showers at same time.
I'm realistic about the fact that there will be a drop in performance when running both showers at same time.
I'm also under the impression that running a tap and shower at same time should not be an issue.

 

[Hot&Cold]

Have you and your g3 installer discussed your needs and demands,you want a decent water system

We did, yes. Why do you ask?

Its always a very good idea to know the finished installation will meet your needs & demands (in writing) it should be part of the contract between yourself and the installer.

Running 2 showers simultaneously is possible,just ask the plumbing installer to select the correct shower mixer valves and fittings to give priority to the showers over the remainder of your installation.

Dont know who your water supply company is but some can legally reduce or increase flow/pressure when they feel like it.ask your water company.

Are you on a water meter ?

 

[Shadoman]

Thanks Old and Cold. It's interesting because I've read on these forums about forming contracts and have everything guaranteed, but everyone who I've spoken to in my area pull out all the disclaimers under the sun. Id pay extra to get this guarantee but so far, having got quotes from 7 different installers, not one of them provides any guarantee. Some of these are Worcester accredited.
Thanks for the advice around the shower valves. I'll definitely take this into account.
We are supplied by Thames Water. I hear what you're saying about water pressure fluctuations and their ability to throttle. I have spoken to some of my neighbors and they have unvented systems and they've never had a complaint about pressure and they've been around here for 10+ years.
They also didn't bother installing bigger water mains pipes, this wasnt even advised to then.
But I understand everyone has different demands.
Do you think then that I should avoid the digging and go with the current pipe situation as John mentioned?

 

[Shadoman]

Sorry, forgot to add. We are not on a water meter.

 

[Keithmac]

You should be very happy at 22l/min at 3bar!.

Mines shocking from the mains, 8l/m (same as whole street!).

 

[Shadoman]

Hi Keithmac, I am for sure! I moved from a low pressure area. It's just that you get so much differing advice from tradesmen, that by the end of it, you don't know where you stand.

 

[Hot&Cold]

Your installer has to install the best setup as possible and consider possible future alterations,your installer has seen the installation tested water flow/pressure under demand (i hope).

No water meter and wanting a flow/pressure upgrade could result in higher quarterly water charges or mandatory meter fitting but your plumber will know that.

love thames water the recycle experts.from pish to tap water...

 

[Shadoman]

Haha, I'm not familiar with Thames Water, what's the deal?
We're not touching the external valve to the upstream road supply (I had a separate quote for this and it was £1500 for TW to upgrade their pipe). Just from the he stop valve to our property. As far as I am aware, that wouldn't result in any change to my water rates right?
With respect to the installers, yes, they've all measured up and said the flow will be acceptable off the 15mil but they all caveat saying if I'm not happy with it then I will need to upgrade the pipe. Which I think is fair enough right?

 

[Hot&Cold]

have trust in your plumber

 

[Shadoman]

I will thanks for the advice.

 

[fezster]

You can have a new supply pipe moled underground which is significantly less disruptive and probably cheaper. You'll still need Thames Water to connect the new supply pipe up. With the upgrade, you may even be able to run two showers simultaneously.