how to drain the central heating system and how to refill

13 Oct 2010
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United Kingdom
hi everyone, anyone have a clue on how to drain the central heating system and how to refill the same. mine don't have any drain cock on the downstair radiators, what valve should i close to drain the system
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i'm not sure about my system but i have 2 cistern tank on my loft of the same size, not sure which one goes to the sink and which on goes to the heating system. my radiators heat up only on top but not on the bottom so i wanted to remove the sludge deposits. oh can u recommend a de-sludger
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you need to tie up the ballvalve in the heating tank

run a hot tap and see which one fills (the one you want is the other one)

turn off both valves drain and remove a rad at a low point in the system

attach a hose to the valve and drain through that

might be worth fitting one of these

or cut a tee in and fit one of these

good cleaner sentinel x 800

if the system is sound you might try fernox ds 40


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