Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi all! We have been experiencing an issue on site where threads have been missing the latest postings. The platform host Vanilla are working on this issue. A workaround that has been used by some is to navigate back from 1 to 10+ pages to re-sync the thread and this will then show the latest posts. Thanks, Mike.
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

New build - low mains water pressure

  • 08-09-2021 5:34pm
    #1
    BobDeBuildere
    Registered Users Posts: 9 ✭


    Dear All,

    I'm looking for some advice from experienced plumbers/self builders.

    I have moved into my new self-built house. All good except for the mains water pressure. I brought it from the main road, down a lane (about 300m) using a heavy gauge 1/2" hydrodare. It comes into the garage and is split at a small manifold...one line goes to the 1,000 litre cold water tank - this feeds the house via a pump; one line goes to the kitchen sink, one to the dishwasher and one to the washing machine. The pressure at the kitchen sink when nothing else is being called is about 4 litres per minute (0.4 bar I think). It's not great but works ok. The problem is when any body in the house has a shower, the cold water tank starts to be filled up from the mains supply and then there's almost zero pressure at the kitchen sink. Also, I can't turn on both the dishwasher and washing machine at the same time or they both start giving off low pressure warning alarms.

    I'm thinking one of the following solutions will solve the problem...

    1. Buy an in-line pump and fit it between the mains coming into the garage and the manifold. Possible problem is that the pump will run dry and not resolve anything.
    2. Run a bigger heavy gauge hydrodare pipe (maybe 25mm external/20mm internal) from the road down the lane and into the garage manifold?

    Any other ideas?...or thoughts/comments would be very much appreciated.

    Thanks

    Bob



Comments

  • #2
    John.G
    Registered Users, Registered Users 2 Posts: 3,550 ✭✭✭John.G


    300M is a fair distance by any standards and IMO not a hope of getting any meaningful flow with or without a in line booster pump which just won't work due to the pipe friction losses.

    I have a bit of that HD hydrodare piping out the back and its 12MM ID so......

    here are the pressure losses at different flow rates for 300M of 12mm piping and for the 20mm which IMO you will have to install. Even your flowrate of 4LPM results in a pressure loss of 1.3 bar.

    LPM Loss (Bar)

    5 1.9 0.16

    10 6.8 0.57

    15 14.5 1.2

    20 24.6 2.0

    you can do your own calcs here.

    friction_loss (pumpnet.net)



Advertisement