Urgent help Please Combi Care Scale Inhibitor

Discussion in 'Plumbing and Central Heating' started by mikebh50, 10 Jan 2009.

  1. mikebh50

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    Hi
    Have just changed the above and we now have no hot water have removed the inhibitor and the hole in the fitting appears to be full of scale (we live in Norfolk so very hard water)is there anything i can do.The water shut off knob below the inhibitor does take loads of turns to turn on or off is this right?
    Any help would be great

    Thanks
    Mike
     
  2. simond

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    So you have changed your scale inhibitor out, and it is immediately blocked full of scale.

    Surely not?
     
  3. mikebh50

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    Hi

    Please see pic

    If i turn the blue end on the tap below the fitting no water comes out.Now should i have touched this and if not how do i get the water to flow again.

    Mike
    mike
     
  4. gas4you

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    Remove the combi care body from the pipe work. You will find that the fitting is completely blocked, by hardened phosphate from the combi care cartridge.

    If you can't clean it out you will have to get another.

    This is a very common problem with these, although at present I have only had the Sentinel ones block, even though they are the same thing.

    Sentinel blame it on the cartidge assembly being less than 1M from the boiler/heat source, but I have had them block at over 3M away :rolleyes:
     
  5. Softus

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    You're right Dave - near me there's an entire estate of them that block up with the CC more than 5m away from the boiler.

    In my experience they're fairly easy to clean out, using twist drills starting at about 1.5mm. If access is awkward then it's easier to remove the entire assembly first.
     
  6. mikebh50

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    Hi
    Thanks for the replys i cleaned the small holes out with a twist drill and we now have hot water but i don't know if its worth getting a new fitting as i don't seem to get any water out of the small bleed screw on top of the cartridge so i was wondering if the water was just going striaght up the pipe and missing the cartridge if this is possible.As for distance from boiler the cartridge is under the sink one side of the house and the boiler is in a cupboard upstair right on the other side of the house.

    Thanks
    Mike
     
  7. gas4you

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    These are designed so that nearly all the water bypasses the cartridge and only a very small amount goes through the phosphate cartridge, just enough to mix with the hard water to help stop scale from forming.
     
  8. oilman

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  9. Softus

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    Did you unblock the vent?
     
  10. OilLecky

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    I concur with the above comments on blockage. I had one where the cartridge would not come out as it was jammed, the neck broke off in the end. I removed the whole fitting to clean out the lump of cartridge top and found that it was almost full of whatever is in the cartridge. I changed it all as it was easier that drilling / cleaning. It is easy to see how, if the old cartridge had come out properly and I'd fitted a new one, then a little extra deposit would have blocked the 15mm fitting completely and no water flow just like the OP got!
    They must have stayed up all night to design these things! (I wonder if they tested them for say...10years, with an annual cartridge change?)
     
  11. ggaylmer

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    Thanks for bringing the issue to light of phosphate deposits blocking Combicare pipework. I've had a Grant external combi boiler for 4 years and have been changing the Combicare cartridge every year. This year I couldn't get the cartridge off easily and there was some foam leaking out of a split in the plastic neck, maybe due to pressure build-up. I took the whole fitting off, managed to lever off the Combicare cartridge and noticed that the small hole leading out of the metal pipework from the Combicare was completely blocked with a hard phosphate deposit from outside to inside(approx 2cm in length). The hole leading into the cartridge was not blocked at all. Obviously the Combicare was completely useless if no phosphate was getting into the water. I wondered how long this had been blocked...maybe several years for all I knew. It would not have stopped water flowing into the boiler as it is a parallel circuit with most water bypassing the Combicare.
    I tried soaking the fitting in strong descaler but it had no effect. Apparently calcium phosphate is very difficult to remove chemically, being an extremely insoluble amorphous deposit. Then I tried drilling into the hole as suggested on this forum but unfortunately my drill bit broke inside the hole and got jammed. These things always happen to me!
    This a nightmare as I will now need a whole new Combicare kit to replace the metal pipework. I've fitted the new Combicare cartridge temporarily but it is doing absolutely nothing apart from filling the gap in the water supply pipe allowing water to bypass it. I'm also no nearer solving the problem of the phosphate scale build up or finding a way to remove it if it does form in the new pipework....maybe better quality drill bits? This is a terrible design fault of the Combicare and is never mentioned anywhere in their literature. No wonder! There is no way to know whether it is blocked without removing the fitting. I wonder how many others are fitting cartridges every year unaware that the fitting is completely blocked and probably has been for some years.
    It might be better to buy a Combimate, instead of another complete Combicare unit, expensive though it is. There's no room inside the boiler for a Combimate but I could fit it to the water supply somewhere in the house. If it doesn't block it might be actually helping to protect my boiler from limescale deposit.
     
  12. igneous

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    Is it me missing something or the fact the op has wound down their prv been ignored?
     
  13. igneous

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    It's always fascinating to read threads with pages dedicated to chemical formulae, ion interaction and co valences etc but rarely useful.

    Whoops wrong thread 😁
     
  14. ggaylmer

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    I don't think it matters how old a post is, it is still interesting and helpful for people like me to be able to read them and for others to read my reply if they have a similar problem.
     

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