Draining system (Combi boiler)

13 May 2014
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United Kingdom
I've replaced/added several radiators and all seems to be water tight but I'm going to give it another week before adding inhibitor just to be sure.

When it comes time to add the inhibitor what I was thinking of doing is draining only one rad and locking all the others off. Doing only a partial drain then adding inhibitor to the drained rad and then refill the system.

Will there be any problems doing this?
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There shouldn't be any problems in doing it that way, I like to change mine every six months for no other reason than I like messaging about. I've done it by draining the system fully and adding it and just draining the one rad, though in my home the bathroom towel rail has a cap on the top which is by far the easiest way to add it for me as its a vertical pour then without faffing about side on with a make shift pourer.
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Similar to what happened to me once before, I was using the Ideal combi boiler, but switched it off before draining the system.

Worked out all OK, no further problems.
Last edited:

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