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Discuss Can I re-use corrosion inhibitor? in the Central Heating Forum area at

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  1. PaulR

    PaulR New Member

    I'm going to attempt some work on my central heating system which will involve partially draining it down, possibly a number of times.

    I have a small water pump, so in theory I could keep the drained water and pump it back into my system. Then I wouldn't have to worry about replacing the corrosion inhibitor and getting the concentration right.

    Is there any reason this wouldn't work? One potential problem I can think of is if the corrosion inhibitor degrades when exposed to air, so keeping it in a bucket would be bad for it. I don't know if this is the case. Any thoughts?
  2. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    No and as you have said which is correct

    Inhb degrades over time and needs refreshing/replacing
    • Agree Agree x 1
  3. king of pipes

    king of pipes Trusted Plumber GSR

    No take the opportunity to drain and flush the system your system water will contain contaminates and the inhibitor will be degraded all systems should be drained flushed and refilled with fresh inhibitor added every 5 years this is my opion.cheers kop
    • Agree Agree x 1
  4. firemant

    firemant Plumber GSR

    You would need a big bucket :eek:
    • Like Like x 1
  5. Ric2013

    Ric2013 Plumber

    I've done it before for a guy who insisted he didn't want new water in the system as it would introduce fresh air and lead to corrosion. I used lots of buckets and poured back into the F & E. It didn't seem to do the system any harm, and the customer's family had plenty of buckets to play with (which were cheaper than inhibitor).
  6. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    But that is introducing air into the system as well?
    • Like Like x 2
  7. SimonG

    SimonG Trusted Plumber Top Contributor!!

    Even as s Yorkshire man I would just buy another bottle of inhibitor.
    • Funny Funny x 3
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    • Agree Agree x 1
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  8. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    I agree and I’m not a Yorkshire man.
    • Funny Funny x 2
  9. PaulR

    PaulR New Member

    Appreciate the advice everyone. I was interested in what the manufacturers advised so I asked them (Sentinel). Their reply:


    X100 does not degrade with air contact and in theory it could be drained from a system and then reinstated.
    I would just like you to note that whilst this could be done we would not recommend it as the system water removed could contain debris. We would always recommend filling with new water and re-dosing with X100.
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  10. Harvest Fields

    Harvest Fields Trusted Plumber GSR Top Contributor!!

    Good advice that mate.:cool::cool:
  11. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    I am as tight as a ducks a*** , and even I wouldnt put it back
    • Funny Funny x 3
  12. Stoney Ground

    Stoney Ground GSR

    Hope he doesn’t get a sealed system, he’ll have you venting rads and saving the air for the expansion vessel :cool:
    • Funny Funny x 5
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  13. turnpin

    turnpin Trusted Plumber

    For what it would cost just renew it while you have an opportunity....while spoil the ship for an ' apporth of tar...regards Turnpin
    • Agree Agree x 1
  14. Ric2013

    Ric2013 Plumber

    What if the OP wants to re-use the less cruddy water on all the several refills but the last one, and then, finally, do a full hot flush with the old water, drain down again, and refill with fresh inhibitor?
    After all, if the system is to be drained several times, this could be a lot of wasted inhibitor.
    I can't see a problem with that approach and, unless the buckets are bought for this single purpose and then landfilled, then the OP should be applauded for avoidance of chemical waste.
    • Dislike Dislike x 1
  15. jonnyswamp

    jonnyswamp Plumber GSR

    FFS, just spend the tenner and put fresh in, if it's only a couple of days in between fills/drains no need for inhibitor
    • Like Like x 1
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