Trying to avoid draining heating system

Discussion in 'Plumbers' Talk' started by DIYDave., Feb 27, 2015.

  1. DIYDave.

    DIYDave. Well-Known Member

    Hi all
    A friends asked me for a hand to change a radiator that's rusty and leaking and the valves leak as well. Have tried nipping up the gland nut but still weeps. System is plumbed in plastic 10mm micro

    Thought as changing the rad we may as well use new valves at same time
    As above, just trying to avoid draining down the system really to make this a quick, straight forward job

    Have seen these squeeze off tools;

    Being a diy'er (so one off job) and tight, could we get away with clamping the plastic pipe either end with a G Clamp and maybe a small block of wood top and bottom of pipe to protect ?

    Realise that this may be a total cowboy approach but as a diy'er, could it possibly work, or maybe someone had done this with success

    Cant see much difference between this method and the correct tool and assume the plastic pipe just spring back into shape once released

    Cheers for your thoughts guys
  2. plumber-boy

    plumber-boy Well-Known Member

    If its a vented heating system turn the boiler off,bung the FE tank in the loft and the vent pipe over the tank this will make a vacuum in the system,and then you can change one valve at a time.I do it all the time as do other plumbers its dead easy.;)
  3. DIYDave.

    DIYDave. Well-Known Member

    Hi PB and many thank for the super fast reply - much appreciated really

    I think it's a combi boiler from my mates description but although I know a tiny tiny bit about plumbing, my mate knows diddly squat !

    I can pop over at the w end to confirm. If it is a combi, I know there will be no tank to bung so is there another method or the cowboy G Clamps !
  4. plumber-boy

    plumber-boy Well-Known Member

    Hi Dave.
    I have one of them clamps but I only use it on MDPE to be honest.
    Other options buy a small freeze kit,10mm dead easy.
    Or put a hose on drain valve and open it up but only vent the rad your replacing,the other rads will hold and that will save you time refilling the whole system.;)
  5. DIYDave.

    DIYDave. Well-Known Member

    Cheers again PB that's a neat trick ! (3rd option)
    Will take your word for it but when I come to do it, I know I will cack myself :eek:

    So hose on drain valve and open, vent and drain rusty rad then remove, remove rad valves and water wont pish out from the pipes or open drain off ?

    I never was good at physics or fluid mechanics !
  6. plumber-boy

    plumber-boy Well-Known Member

    That's it Dave one valve at a time and leave the hose on the drain off,the rads will hold their water so all your doing is releasing the pressure and water in the pipes,so once the hose stops running you get plumbing,if your not confident then just drain the whole system and always make sure the boiler is off.
    GOODLUCK Dave.
  7. DIY, as plumb-boy says.

    Switch offski the combi at its power supply. Look underneath the boiler - you'll find the flow and return pipes and they'll have quarter-turn shut-off valves on them. Turn them offski fully.

    That's the vast bulk of the stored pressure taken care off right there, nicely trapped inside the boiler's exp vessel.

    Then shut off the valves on each rad fully - make sure you record exactly how many turns/parts of turn the lockshield end takes on each valve.

    Then schtick a pan under the valves of the rad you are removing and slacken them offski - catch all the water. Job done.

    You could even get away with not shutting off the other lockshields, which will save a lot of bother; as said above, it's amazing how little water will come out simply due to the fact that no air is going to easily get in. So, chust remove the valves of the rad you are swapping, making sure you have plenty containers and towels at the ready - once the rad is empty, very little extra water will come out - chust a slow trickle or drips, easily caught.

    But, be prepared too - get the new pair of valves all ready for a quick swap - whatever you need. Once the new valves are on, you are sorted and can open up the boiler to the circuit and fire it all up again.

    Obviously your boiler pressure will need topping up againski.
  8. Dave does Gas

    Dave does Gas Well-Known Member

    Don't forget to add an inhibitor when you refill the system
  9. DIYDave.

    DIYDave. Well-Known Member

    Thanks again guys for all the advice and also about adding inhibitor

    Was actually thinking myself if inhibitor would be needed but I'm a bit confused as to how much water can be expected to be lost if using the above method, ie;

    Hose on drain off and open up
    Do not vent any other rads
    Vent and remove just damaged rad
    Replace one rad valve at a time

    So I guess this causes a vacuum which holds the majority of water in the system - rads and pipe work ?

    So how much water will be lost via the hose and where is this water from / pipe work or rads ?

    Honestly not doubting the advice lads but would just like a little more understanding for my own benifit

    Thanks again for the advise so far
  10. plumber-boy

    plumber-boy Well-Known Member

    It will only be a small amount of water so don't worry to much about the inhibitor, the water will be just what is sitting in the pipe work and the rad your replacing Dave.
  11. DIYDave.

    DIYDave. Well-Known Member

    Ok thanks PB

    Leads on to another question now ......................Arghhhhhhhhhhhhhhhhhhhhhhh you might say :eek:

    How long is inhibitor left in a system active for and does its "magical properties" diminish over time

    Unless you've had the system drained or flushed, the same inhibitor could be in there for years and years I guess. Do you just top up with new stuff in that case and is there any problem in having too high a concentration of inhibitor in the system

    So many questions now !
  12. plumber-boy

    plumber-boy Well-Known Member

    Hi Dave.
    You can top it up if you like, I wouldn't worry to much with regards to how concentrated it maybe its not a science mate, just don't flood the place and blame me.:eek::eek: :)

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