Problem with toilet fill valve

Discussion in 'Plumbers' Talk' started by ProDave, Mar 11, 2010.

  1. ProDave

    ProDave New Member

    I'm re fitting a new bathroom in a flat. Trying to use as much of the existing plumbing as possible, and I have encountered a problem with the toilet fill valve.

    The old toilet was filled with water from the cold water header tank, and as that header tank is on a stand above the hot water cylinder in the adjacent airing cupboard, the water pressure is extremely low, about 5ft of head.

    The old toilet had a conventional float valve. The new one has a bottom entry Torbeck valve, similar to Screwfix part number 75136

    The problem is firstly the fill is extremely slow (much slower than the old toilets fill valve, which was already pretty slow), but when full it does not shut off, in spite of the float floating up as far as it can.

    Am I right in saying these types of fill valve won't work on such low water pressure? I have removed the flow restrictor which the instructions say to do for water pressure below 1 bar.

    If this is the wrong type of valve for this application, what can I use instead. I really can't see that there is enough room in the small cistern for a conventional float valve.

    The only other (unquestionably better) option would be to re plumb to get mains water to the WC, but everything is boxed in and it would be a major job to gain access to feed a new pipe, so that really is a last resort. I would prefer to find an alternative fill valve that will work on this very low pressure.
     
  2. G Brown

    G Brown New Member

    Fluidmaster
     
  3. palavaman

    palavaman Well-Known Member

    fluidmaster.
     
  4. palavaman

    palavaman Well-Known Member

  5. britishblue

    britishblue New Member

    Fluidmaster is absolutely the wrong filling valve for very low water pressure, as I found out when fitting a bathroom suite where the toilet cistern had previously been supplied by mains water and was now tank fed. The cistern took forever to fill.
    Spoke to Fluidmaster who, after a bit of persuasion, supplied a much softer internal washer (I think it was red rather than grey). This resulted in filling speed being tolerable, but still fairly slow.
    Fluidmaster are well designed and reliable valves but totally unsuitable for very low pressure water supplies.

    BB
     
  6. palavaman

    palavaman Well-Known Member

    experience is the best teacher:D

    i am yet to have a problem, so will continue to use. you say its the wrong valve for low pressure systems, ok. you say you encountered difficulty in the past, ok. you do not tell the op or anyone else what is the best alternative????

    .....toilet cistern had previously been suplied by mains water. ok, so what was the relation of the cistern, pan, or toilet to the CWSC????? if there's hardly any head, then ofcourse, you'll have issues.
     
  7. britishblue

    britishblue New Member

    Head of water was only about 6ft. I didn't say it was necessarily wrong for low pressure systems, but it is for very low pressure systems. Fluidmaster themselves say this on their website "LOW PRESSURE APPLICATION: If toilet cistern takes longer than 4 minutes to fill replace the existing black seal with a red ultra low
    pressure seal"
    Unfortunately, they don't give any specifications or quantification of what is "low pressure".

    BB
     
  8. ProDave

    ProDave New Member

    So, apart from possibly needing a different washer, it looks like fluidmaster is the one I want.

    But to question the one I have in more detail, does the fact it doesn't shut off indicate it's got a fault? or is that normal because of the very low pressure?

    I had to drain the header tank completely to replace a stuck gate valve and in re filling it it stirred up a lot of sediment in the bottom of that tank, so I wonder if all that's wrong with the one I have is a blockage?
     
  9. bath master

    bath master New Member

    Had the same prob with low pressure. Fit old float valve and fit the LP trumpet. Even tried torbeck and had prob with it shutting off.
     
  10. ThreadJacker

    ThreadJacker Active Member

    Spooky,

    I've just got in from a job with exactly the same problem, tank fed Torbeck that was overflowing.

    Cistern too narrow for conventional float valve so had to fit a black washered Fluidmaster.
    Tested it a few times and it was a two and a half minute fill up.

    I will get some red washers just in case though.

    I know now from my own experience that Torbecks are unsuitable junk.
     
  11. G Brown

    G Brown New Member

    Lads! Any experienced pro will carry different washers and inserts on his van to cope with different pressures ;)
     
  12. tackleburger

    tackleburger New Member

    I have used Fluidmaster for ages now and never had to use the red washers I have thre which I purchased over a year ago nver been used.

    Torbeck's with the small float are ****, I did notice the other day in a new cistern they are now making something similar to a fluidmaster. Another alternative for a tight space is the Wirquin good on LP and the float is encased so if the valve touches the side of the cistern the float still operates freely.
     
  13. Rowdey

    Rowdey Member

    Weird had same situation today - tank fed new Multiquick cistern (needed the flush pipe to be adjustable once external floor contractor has come in, so lay off..!) and the fitted Torbek worked well once and then refused to shut off, despite twice removing and thoroughly cleaning..

    Replaced with a similar-ish style Dudley valve (recently on offer at Plumbase me thinks..?) and all very good with quick fill up. Recomended.
     
  14. Mark Toplis

    Mark Toplis New Member

    Looking for some help guys. I live in a relatively new property and recently the bottom fill valve is not fully shutting off causing it to keep filling and overflowing into the bowl. It is very annoying trying to sleep when you can hear that!

    I brought a fluid master one from screwfix but when i have fitted it this one is not shutting off at all. I have tried flushing the valve to clear any dirt and i have also ensured the top is tightly fastened but the same. As soon as i put the old one back in that was shutting off better but still a slight drip.

    Any other ideas?
     
  15. tore81

    tore81 Screwfix Select

    I have seen somewhere there could be grit or dirt under the syphon mechanism.

    Also if it's mains water to lessen the pressure on the isolation valve. Worth a try
     
  16. Mark Toplis

    Mark Toplis New Member

    This toilet is in the en suite and has no isolation valve. I had flushed out the mechanism and it didn't seem to make any difference
     
  17. tore81

    tore81 Screwfix Select

    I thought every toilet should be fitted with an isolation valve. It's new build how long installed.

    What I mean dirt gets trapped under the washer causing it to overflow. Is the toilet linked to your other toilet must be one there if it's new build
     
  18. dynomite

    dynomite Member

    Imo torbeck valves are best for low pressure, used a lot of the telescopic ones and always removed the restrictor but kept filter in.obviously there was always few faulty ones as with everything else.
     
  19. MrsMasonWebb

    MrsMasonWebb New Member

    Hi Mark - can I ask how you fixed the problem? I've had exactly the same and cant get a solution.

    ANY help is greatly appreciated!!

    Thanks!
     
  20. Joe the Plumber

    Joe the Plumber Screwfix Select

    Have a search for 'Builder Depot', and part number SKU: P000339.

    Although you'll probably need to modify it, these valves can be made to fit and work on low pressure systems.
     
    MrsMasonWebb likes this.

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