Thursday, November 15, 2018

Draining down central heating

February 2, 2012 by  
Filed under Guest Articles on Low Cost Heating

How to drain down the central heating system in a home. Brought to you by

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25 Responses to “Draining down central heating”
  1. ultimatehandyman says:

    LOL, People will always need plumbers ;-)

  2. VOICEofTRNC says:

    Come on geezer! Making us plumbers lose out on the moular!

  3. ultimatehandyman says:

    I’m just off out. Might be best if you ask in the forum, just follow the links from my channel page, they will advise you ;-)

  4. pskerries says:

    @ultimatehandyman I have to move the radiator,the floor have taken up and there is no thermostatic valve,both of the two valve looking same.I’ve already turned on the heating to know which one is carrying the hot water but after opened up the valves there was both hot.any ideas?
    thanks again!

  5. ultimatehandyman says:

    The flow pipe normally has the thermostatic valve fitted to it.
    Thanks for the coment

  6. pskerries says:

    @ultimatehandyman the video was great.could you tell me how can I know which pipe is the hot flow and which one is the cooler return?

  7. ultimatehandyman says:

    Do people complain so much about advertisements on the TV or in the newspapers!

  8. pskerries says:

    f*****g advertisement!

  9. ultimatehandyman says:

    Thanks for the comment ;-)

  10. TK42138 says:

    Well explained. 

  11. ultimatehandyman says:

    That is brilliant- well done ;-)

  12. SifterOfwheat says:

    Gawd bless you! You gave me the confidence to drain her down and fit a new actuator motor; a job for which British gas would have charged me upwards of 200 quid. I did it for 30 quid with a part from ebay!
    Thanks again buddy.

  13. ultimatehandyman says:

    You can normally remove any air by bleeding the radiators during refilling.
    Inhibitor should be added whilst re-filling.

  14. SifterOfwheat says:

    Is draining down going to cause any complications with SEALED CH SYSTEMS? Anything I need to look out for when I’m refilling the system? I’ve heard of air pockets forming and all sorts.

  15. Kropotkinskaya says:

    @Kropotkinskaya Thanks so much. The most helpful plumber ever!

  16. ultimatehandyman says:

    Yes, if you close the isolation valve and then press down on the ball valve in the tank no water should come out of it. If the isolating valve does not work you can stop the header tank from filling by placing a piece of wood across the top of the tank and then tie the ball valve up, which will prevent the tank from filling.

  17. Kropotkinskaya says:

    @ultimatehandyman wow. ok. makes total sense. Just hope that is indeed the isolating valve. If not, there’s always the trick with the ball valve right?

  18. ultimatehandyman says:

    so you should not need to open a radiator bleed valve as air can get in via the header tank- which will allow all of the water to drain out. You only need to open an upstairs bleed valve if you have a sealed system!

  19. ultimatehandyman says:

    Hi, No problem.
    If the pipe going to the ball valve has a valve with a red handle, this sounds like a gate valve, so close that and it will stop the header tank from filling. When you connect the pipe to the drain off valve and open the drain off, the water will start to drain from the system and the header tank- continued-

  20. Kropotkinskaya says:

    @ultimatehandyman Firstly, thanks very much for such a swift reply. Secondly, is the isolating valve a red, circular, metallic wheel like thing on the header tank?

    Lastly you say”you can safely open it and no water should come out”When you say it, are you talking about the drain valve downstairs or the upstairs bleed valves? If I bleed downstairs then upstairs level will drop?Sorry! Just want to avoid a mess!

    Thanks for clarifying, and thanks again for you help. Really appreciated.

  21. ultimatehandyman says:

    Question two-
    Once you have opened the drain valve downstairs and drained out some water it will be below the level of the upstairs bleed valve, so you can safely open it and no water should come out.

  22. ultimatehandyman says:

    Hi Kropotkinskaya, you are not thick, you have the good sense to ask before you try something you have not done before ;-)
    If you have a conventional system the header tank will be in the loft, it will be a tank with a ball valve in it. Some have an isolating valve and others do not. If there is no isolation valve you can tie the ball valve up using a piece of wood and string, this will stop the ball valve filling.

  23. Kropotkinskaya says:

    Hi ultimate handyman. 2 questions, and sorry to be thick.

    Firstly, how can i isolate the water going into the header tank? Where will I find it (is it a switch or something on the tank itself?

    And secondly, if I bleed the upstairs radiators first, won’t water come out? Or will openng the drain off valve of a downstairs radiator mean that that won’t happen?

    Again, sorry for being thick – never done it before.

    Thanks for any help

  24. ultimatehandyman says:

    No problem at all.
    Thanks for the comments!

  25. rihssty says:

    Really appreciate your help. I’ll make sure that I won’t forget the inhibitor. Thank you very much.

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