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Discuss Replacing radiator and draining systems in the Plumbing Forum area at

  1. Dan1706

    Dan1706 New Member


    I will be changing a radiator in my downstairs toilet. Looking for advise on best order to drain and fill system and any potential issues with doing this. I have gravity fed system.

    Any help is appreciated. Thanks
  2. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Is it a straight swap or does it require pipework? Wider/narrower???
  3. Dan1706

    Dan1706 New Member

    Its going to need a bit of pipework alteration unfortunately. I guess there is any easier way if its the same size? What would change if it is not?
  4. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

    Same size you can just turn off radiator valves, drain just that rad, replace and open valves.

    If you’re tweaking pipework then turn off heating system, isolate mains, drain till no water comes out of rad valves you’re working on, do your pipework, replace rad, refill and deal with any potential airlocks
  5. Rob Foster

    Rob Foster Top Contributor!!

    In this order. Turn off boiler let system cool down. Attach hose to lowest drain off point. Turn off supply to he little tank in roof. Open drain off and let water out. Beware that the rad you want might not drain f it’s dropped with no drain off. When dirty water stops undo valves at either end of rad. Lift and pull off one end drain into washing up bowl or if enough space flip it upside down with bleed closed. Dump in garden.
    Play plumbers and fit new rad, open valve to little tank again test with clean water drain again and add inhibitor into the little tank . Fill up bleed everything inc. pump lowest rad 1st highest rad last. Switch system on, check for leaks again, crack open a beer get thanked by wife ..centralheatking
    • Winner Winner x 1
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