New Water Main

[YTPreston]

Hi All,

I was hoping you guys could help answer a few questions i have.

I live in a large Victorian house, with a shared lead supply. I hoping to replace this with a 25 or 32mm MDPE pipe. I have a 300l ACV Cylinder with a 50kw ACV system boiler. There is currently a 22mm pipe going from internal stopcock to my cylinder roughly about 12m. I have 2 bathrooms, 2 kitchen sinks, 4 toilets and 4 wash basins. I measure the pressure at my outdoor tap with no other taps running it was roughly 4bar.

The new pipe run is roughly 20m to the pavement stopcock. This will be done with a moling machine.

United Utilities have refused to connect a 35mm pipe only a 25mm under the lead replacement scheme.

PS UU are coming out to test flow and pressure at mains next week, will report back with there findings.

Is it worth having the 35mm pipe?
Will the 25mm pipe be adequate?
Shall I lay the 35mm pipe but then get UU to reduce it down to 25mm at connection?

Running multiple sinks is not an issue, It is when the bathroom shower is in use. it has a 400mmx300mm shower head with a required pressure of 2bar plus. When this is in use and someone turns the kitchen sink on, the flow reduces and pressure. The valve is plumbed via 22mm copper for both hot and cold.

Will running a new supply solve the issue?

 

[Millsy 82]

A 25mm main will more than likely be Alot better than what you have already, can't see the point in running bigger then reducing it down myself.

 

[ShaunCorbs]

They will say no as there paying for it what about saying you will pay the difference

I would see what uu say is the flow your going to get ish

32mm would be better as the internal bore will be around 25-26mm ish

 

[chris watkins]

Unless they are going to replace the communication pipe from the street main to your boundary stop valve (as well the services pipe) it will make little difference to the flow rates you can achieve.

 

[Welder]

Unless they are going to replace the communication pipe from the street main to your boundary stop valve (as well the services pipe) it will make little difference to the flow rates you can achieve.

Chris is, as always, spot on. Your actual flow is governed by the smallest orifice in the line. If you have a 35mm supply but a 1/2" meter then you have an expensive 1/2" supply.

 

[YTPreston]

thank you all, will i see a big improvement as its a big investment?

 

[chris watkins]

No, not likely unless the communication pipe to the mains in the street is also upgraded.

 

[YTPreston]

Sorry I meant, if I upgrade to 25mm will I see a big improvement compared to the current shared lead supply?

 

[chris watkins]

What size is the existing shared lead main supply?
What is the current flow rates (at different times through out the day)?
What does it reduce to when the other supply is used?
It just isn't possible to say unless we have more information or are on site.
Sorry but batteries have run out on my crystal ball.

 

[YTPreston]

Apologies,

The lead pipe coming in form next door has a internal diameter of about 22mm.

The flow does not drastically reduce when sinks, toilets and basins are used in my house regardless of time of day.

Its hard to say the effect on the flow rate when the other supply is used, as I do not know the set up next door. What system they have or type or number of bathrooms. But when I use my shower and the kitchen tap is open, there is a marked reduction in flow.

From my understanding the lead supply comes into next door's cellar. From there cellar it branches off through the wall into my cellar. I did have a leak a few months ago from the lead pipe, Homeserve came and replaced the lead pipe with a blue pipe, which connects into next doors lead supply. They used a 25mm pipe.

 

[chris watkins]

It could be restricted on your leg then.
Separating the two supplies is got to be a good thing but as to wether it will sort the shower out, it isn't possible to tell you.

 

[YTPreston]

What information do I need to check if a new 25mm pipe will help reduce the issues with the shower, as I am planning to install a another main powered shower in the future, although with a much smaller shower head.

 

[Welder]

As already mentioned, your supply is only as good as the smallest dia part of it. You'll need to understand from the waterboard what that dia is. Again as already mentioned, if they connect a huge dia pipe to a small 1/2" meter then your potential is strangled at birth!
(Note to self. Try to use more appropriate language...)

 

[YTPreston]

Hi All,

I had UU out today.

They confirmed they will replace there section of communication pipe with 25mm pipe to match my 25mm pipe. This is the biggest they would do without charging a new connection fee.

Current pressure at boundary stopcock is 5bar with a flow rate of 39 ltr.

So with this information would you guys say it is worthwhile replacing my lead with a 25mm supply?

 

[ShaunCorbs]

How much is the connection fee ?

 

[YTPreston]

He said minimum 2k

 

[ShaunCorbs]

You should be fine with the 25mm but I wouldn’t be too surprised if your figures end up around the 30lpm mark