Plumbing Advice Needed.

Discussion in 'Plumbers' Talk' started by Oly1978, Sep 12, 2017.

  1. Oly1978

    Oly1978 New Member

    Hello, This is My first post on here so please go easy. lol

    Im in need of some help and advice and i thought this would be a good place to start as im in ScrewFix every other day at the moment.

    My self and my wife bought our first home a few months back now and are currently in the process of completely renovating it.

    Its a semi detached Ex Council bungalow in Cornwall, we literally spent all the money we had in the world to get the mortgage, so before anybody tells me to just get a plumber in, the simple reality is we don't have the money to pay anybody for the work.

    The whole house needs re plumbing, we literally don't have any running water whatsoever at present and im just about to start the first fix stage routeing the copper pipe to where my sinks bath and boiler will go.

    The bungalow will eventually have a total of 7 rads, 1 bath 2 sinks,( kitchen and bathroom( and we will have a new combi boiler installed (professionally)

    My first question is that the old mains inlet was only 15mm copper coming off a 25mm MDPE Pipe with stop cock. Should i upgrade this to a 22mm pipe? Will this benefit? and do all boilers need a 22mm copper inlet and outlet? or can i go from 15mm up to 22mm for the boiler.

    i might add that the water pressure is seriously low where we live so i will be installing a salamder homeboost system. By doing this will this eradicate the need for a 22mm mains pipe from the MDPE outside?

    ive drawn a quick sketch of the plan, if anybody can cast an eye over it to see if this is viable that would be great.[​IMG]

  2. Pollowick

    Pollowick Well-Known Member

    You are starting afresh so don't cut corners and also think about what you might need in future.

    Upgrade it to 22mm especially with low pressure, you don't want any unnecessary restrictions and the moment you put 15mm in the run that is it, putting 22mm after will not help out.

    I will ask - how good are you at soldering copper pipe and fittings? If you can do it, then fine stay with copper if you wish. If you are unsure or need plenty of practice then consider using Hep2O push fit with plastic barrier pipe. A lot easier and quicker to install for the unskilled.
  3. Oly1978

    Oly1978 New Member

    Thanks, I thought as much, does the plan look ok where I go from 22 down 10 15, for the mains water inlet, I tried a few goes at the copper and pressure tested all went well, I used the Yorkshire pre solderd fixings, I know most plumbers think they look ugly but as it's my first time I figured this would be the sensible option, also you won't see any of the copper pipping in most of the house anyway? It will be mostly hidden behind walls and in the loft.

    Is it ok still to run the hot in 15 from the combi boiler or should that be in 22 then knocked down to 15 when joking to taps and rads?

    Also the cold return on the rads? 15 ok there or again 22(

    Thanks for all your help.
  4. Dave does Gas

    Dave does Gas Well-Known Member

    Stick with the copper if you feel competant soldering as it has a proven lifespan and is rodent proof.
    There is no real need to run the cold in 22mm but it wont hurt.
    The hot will be a 15mm feed of the boiler so leave it all at 15mm
    With regards to the heating system run the main part both flow and return in 22mm then reduce for each rad to 15mm
    Good luck with the project, keep us informed of how your progressing, maybe a picture or two.
  5. Pollowick

    Pollowick Well-Known Member

    Given that teh OP says he has low pressure and probably thus flow rate, I would still keep the cold in 22mm until it is T'd off to each location such as WC, basin &c.
  6. Oly1978

    Oly1978 New Member

    Just spoke to next door neighbour and he said he has his main inlet at 15mm, had new system put in by a plumber 5 years ago and told them that the pressure is so low in this area it would make no difference going up to 22?

    Anyway I think I may carry on with the advise from this thread and also install one of the salamander home boost pumps under the sink directly inline with my mains inlet, looked at reviews and looks good, that should sort the pressure and glow rate out? Right?

    All hot water will run in 15mm from combi.

    Rads will be fed with 22 dropping to 15 when needed.

    Just spent the last few hours with my pipe bender making some lovely bends, along with a few right cock ups... lol.

    Thanks again for all the help
  7. Pollowick

    Pollowick Well-Known Member

    I have not seen one in use, but there are cylinders which take the incoming cold and pressurise it up to a fixed level by use of a pump. Then it feeds to house at high pressure, then as pressure drops below the desired level it will top it up.

    I just cannot think what they are called ...
  8. kiaora

    kiaora Active Member

    Just an observation, have you actually measured the pressure?

    Very often it's the flow that's poor, and it's the pressure that gets the blame!

    So it's is , in my opinion, very important to check the water pressure, you may find the pressure is ok, ?

    If it is ok, the work required is different....

    KIAB likes this.
  9. Oly1978

    Oly1978 New Member

    Thanks Peter, was going to pop to Screwfix this evening to grab a pressure gauge.

    This one should do right?
  10. Pollowick

    Pollowick Well-Known Member

    That will be fine. See what the pressure reading is with nothing else tunred on, then again with the kitchen cold, then with the bath running too.

    Also, can you time how long it takes to fill a 5 litre saucepan, or measure how much you get in 10 seconds. From either of those you can get the flow rate.
  11. Oly1978

    Oly1978 New Member

    At present I don't have a bath or a tap or a boiler, only a little bit of pipe work that I installed last night.

    I can certainly measure how longboat will take me to fill 5 litres.

    I'll do this tomorrow evening and report back.

  12. Pollowick

    Pollowick Well-Known Member

    That will give the static pressure and potential flow rate. If you can, see what the gauge reads when you are doing te flow rate test too.

    MBPLUMB New Member

    upgrading the size of the pipe will not increase the pressure only increase the flow rate.

    if the flow rate is currently poor - look into how old the current stop tap is. remove and replace can significantly increase flow rate if the tap is very old.

    look into underfloor heating rather then rads not very expensive and easier to fit then you think.
  14. Oly1978

    Oly1978 New Member

    Thanks for the advice, the stop tap looks about 5-6 years old as is attached to a blue 22 MDPE PIpe that replaced the old lead pipe I would imagine, looks ok but might switch it out for the sake of a few quid anyway whilst I have dug up the outside to fit the new incoming mains pipe anyway.


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