Very low hot water pressure

Discussion in 'Plumbers' Talk' started by John Brown, Nov 28, 2013.

  1. Yes please.

    But bear in mind we can't all dangle 'that' into the tank and expect it to be long enough to plug the outlet :cool:.



    Sorry - do you mean a trick to drain the hot tank?
     
  2. tom.plum

    tom.plum Screwfix Select

    ok since you've shown an interest, I'm gonna make a vid of this too,

    no need to drain the 'hot tank' (cylinder) as known to us plumbers, if the gate valve or stoptap is above the height of the top of the cylinder,

    using a credit card/debitcard/nectar card or a piece of plastic a similar size, smear a bit of silicone grease over the surface of the card and hold it against the outlet inside the tank ( buttered side to the outlet), then get someone to open a hot tap. the suction from the tap opening will form a seal to the out let,
    now it safe the work on the cold feed pipe,

    ;)
     
  3. meady

    meady Member

    As much time as things like this can help due to not having to drank the cold tank down I still always prefer to do so anyway.

    What happens if one day something happens and the bung lets go. You then Have 50 gallons of water trying to get out of an open ended pipe with no way of stoping it, not my idea of a good time if I'm going to be honest :)
     
  4. I suspect that the gate valve is fitted well below cylinder top height. Tsk - why so plumbers do that :D.

    And possibly no drain cock?

    What manner of sadist installed this tank?



    snigger
     
  5. plane-it

    plane-it Member

    In my case it was the gate valve after the cylinder on the pipe which feeds the hot taps, not the one on the input side coming from the header tank. When I tried to drain the cylinder via the drain cock it leaked everywhere (water came from the key area, probably also corroded) so I had to drain it via the downstairs taps.
     
  6. tom.plum

    tom.plum Screwfix Select

    you can't drain the cylinder through the taps, if the drain off does't work ( and they almost never do) you have to syphon the cylinder,
     
  7. plane-it

    plane-it Member

    True.. if you mean completely drain the cylinder, but as it turned out for just replacing the outbound stop tap I didn't need to empty the cylinder just take off the header-to-cylinder water via the taps and change the stop tap.
     
  8. Out-bound valves are unusual, afaIk. Usually it's on the cold feed to the bottom of the hot cylinder = inbound.
     
  9. tom.plum

    tom.plum Screwfix Select

    I suspect plane-it has a fortic cylinder, they have an internal vent, so a gate valve out bound is OK, but i'm just a guessing, :confused:
     
  10. plane-it

    plane-it Member

    Interesting comments, I am new to plumbing around cylinders, there is a stop tap in the loft on the header tank output that goes down to the cylinder. A fortic cylinder?... Off to google fortic.... Doing renovation on this place is fun, heating had under concrete central heating pipes leaking into the ground among many other horrors!... almost all fixed.
     
  11. plane-it

    plane-it Member

    Just thought about why there's a stop tap on the outbound... the hot can come from the cylinder or the combi boiler, the previous onwer had isolation valves installed to allow switching should one fail. I will be fitting a check valve after the stop tap just in case any one should ever open both valves and start a major cascade from the header tank.

    Just checked... not a Fortic cylinder just a simple old fashion single copper cylinder.
     
    Last edited: Dec 1, 2013

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