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Replacing last section of iron water main with copper

Discussion in 'Plumbing and Central Heating' started by wobbly2, 10 Sep 2021.

  1. wobbly2

    wobbly2

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    Location:
    Berkshire
    Country:
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    The iron water main in my house (a bungalow) rises to the stopcock through a suspended wooden floor in the airing cupboard in a very inconvenient place. It is right behind the cupboard door about 4 inches out from the side wall and along with poorly located heating pipes restricts the use of the cupboard floor. I would like to relocate these pipes. See photo.
    SDC13620.JPG

    I don't foresee a problem with relocating the 22mm heating pipes to below the floor especially as I have already installed a system drain cock elsewhere, my concern is moving the water main.

    What I would like to do is replace the section of 1/2" (?) iron water main pipe that rises through the floor and the old seized stopcock with a 1/2" mail iron x 15mm compression brass adapter and new 15mm copper pipe. The new pipe would then be routed more to the side wall to give better access to the cupboard floor. My concern is that this idea may breach Building or Water Regs or otherwise be unacceptable.

    The cupboard is in the middle of the building so should be well sheltered from all but the most severe cold weather.

    Any help would be much appreciated including comments on the other pipework.
     
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  3. oldbuffer

    oldbuffer

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    1. Don't see anything wrong with what you want to do from a Building Regulations, Water Regulations or workability point of view.
    2. Other things you might like to consider:
    2a. The steel pipe looks like 3/4" to me. For iron pipe, the size (1/2" 3/4" etc.) refers to the inside diameter of the pipe. If you ever wanted to go the unvented hot water route, you might change the 15 mm to 22 mm as far as possible. If you will never go unvented, stick with the 15 mm.
    2b. You could consider replacing the working stop cock with a full bore lever valve. Provided you left a readily available access plate / hole, and some sort of sign, this might enable you to put all the cold water pipe work under the floor.
    2c. I assume the drain off cock is to drain the heating system. Not much point putting that under the floor as no-one will be able to get a hose on it. Perhaps move it to the vertical drop from the boiler return pipe and if necessary fit another lower down in an accessible place.
     
  4. wobbly2

    wobbly2

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    Location:
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    1. That's great.

    2a. Using a Vernier the steel pipe measures 19.33mm O/D give or take a bit for rust and crud etc. I'm aware iron pipes are measured internally and had guessed with 19.33 O/D the I/D must be 1/2". The connections appear to be 1/2" pipe to 1/2" x 3/4" reducer to 3/4" coupler to stopcock. The thread from the bottom of the stopcock looked to be 1/2 male but I only undid it a small amount so I'm not sure. See photo

    SDC13621.JPG


    Not to sure what you mean by going unvented hot water, unless you mean sealed hot water storage system- perhaps electrically heated. The existing hot water is from a combi boiler which I thought was unvented anyway or is that wrong?


    2b. I was considering replacing the stopcock with a lever valve as suggested but so far I haven't found one that is WRAS approved and definitely suitable as a stopcock replacement; been scratching my head over what is and what isn't acceptable. Placing the cold water pipes under the floor is a good idea, which I hadn't thought of but I am also thinking of installing a cold water drain cock, scale reducer (which I have), sediment filter and pressure reducing valve (which I have) to the water main. The scale reducer and pressure reducer presumably could go under the floor but the sediment filter I guess should be more readily accessible?

    2c. The drain cock in the photo is for the central heating but it is seized and I recently fitted a new one to the pipework next to the back door plus replaced the washer in another that dribbled below one of the radiators; so there are alternative drain points. When I reroute the 22mm heating pipes I will install a drain to the outside wall adjacent to an open gulley so the system can be fully drained; at present it only drains to the lowest drain cock and leaves the pipework below the floor, which is most of it, full.

    I'd be grateful if you could also advise on the following:
    • a suitable lever valve to replace the stopcock.
    • is there a particular order I should install the other items mentioned? I assume it should be Stopcock/lever valve -> Drain cock -> Scale reducer -> Sediment filter -> Pressure reducer.
    • a WRAS approved sediment filter with reusable/washable filter media e.g. the "Spin down" type that has a back wash function. I found lots of the "spin down" type on eBay but the sellers don't state that they are WRAS approved or suitable for potable water in the UK and I haven't found any other suppliers that sell them except at extortionate prices. I want the filter because the iron water supply pipe is shedding rust particles that I don't want to get into the boiler DHW heat exchanger, washing machine or shower valves let alone me. The rust shedding was particularly bad just after moving into the property a couple of months ago, although it has greatly eased now but I'd still like a filter until I can get the supply pipe changed.
    Once again any help would be much appreciated
     
    Last edited: 10 Sep 2021
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