Hot water trickle.

[sra]

Can someone help please.

For some months now my hot waters dropped to a trickle.
Are there possible causes for this or can i somehow boost
the pressure by means of a pump which would be preferable
as the pressures not all that effective at the best of times.

Thanks

 

[gas4you]

We need more info on your system. Combi, h/w cylinder, mains pressure, gravity fed from cold tank in loft?

Unfortunately we are not mind readers with a crystal ball

 

[sra]

Ok sorry, well im not to good plumbing so bear with me
i have a cuboard which contains a boiler, hot water tank and
a header above it i guessing my supply relies on gravity not
sure though.

 

[gas4you]

First check the large cold tank in loft for blockages over the 22mm outlet pipe.

Then turn off 22mm gate valve in pipe feeding bottom of h/w cylinder. undo bottom nut and put bucket underneath, open gate valve, if water flows freely then problem is after this point.

You could put hose between cold mains tap and hot water tap and open both to see if cold mains pressure will blow back any possible blockage.

if none of these work you may have a blockage/scale formed at top outlet on h/w cylinder (in pipe work)

 

[sra]

Right firstly i have no loft i live in a flat, so the cold water tank literally
sits on top of the hot water tank bout a foot above, so its not very high.
Also i recently replaced the infeed valve on the cold water tank as the hot water would run dry as the old valve was scaled up, is it possible that i may have pulled some crap through the system by running the water out.

 

[John_D]

Hi what you have is called a FORTIC cylinder. The flow of hot water in a new system is defined by the height of the cold water in the system "the head" the pipe that feeds water from the cold section on top to the bottom of the hot section is internal (in the bulge on side on cylinder). I would replace the cylinder. Check out the environment and consider Megaflo.

YOU MUST BE QUALIFIED TO INSTALL UNVENTED CYLINDERS

 

[JohnD]

(not the same one )

If it has recently got worse, you might be right about a blockage. It is not unusual for wildlife to drown in water tanks. Can you peer into the tank on top with a torch? Maybe a mirror if access is tight? Can you see scale, feathers, bones or small furry bodies? if so, empty the top tank and clean them out. The blocked pipe may need back-flushing.

Check that the sink, basin and bath hot taps have all got slow. Then you know the trouble is before the supply branches off to individual taps.

If it got slow on refilling after draining, and has never improved, it might be an air lock. Low gravity feeds get these easily. Do any of the cold taps come from the tank, or do they all come off the mains?

Do you have a sink mixer? Or hot and cold supply e.g. to a washing machine?

IANAP

 

[sra]

Thanks for the help,
the cold water is straight from mains no problem with that, i have a mixer tap on the bath.

 

[JohnD]

Do you know how to put a hose between hot and cold taps, and let the mains pressure squirt up the hot pipes to clear airlocks or loose blockages?

 

[Rotunda82]

When you fitted the new ball valve did you check that the water is filling to the correct level ? and that it is functioning properly ?

Also just to check - is it all of the hot water outlets or just one ? ie not a tap barrel that needs adjusting ?

 

[sra]

No explain how you use a hose from cold to hot please, i have an idea but
not sure really.
I did check the new valve is working properly and filling appropriately.

 

[JohnD]

No explain how you use a hose from cold to hot please, i have an idea but not sure really.

you get a hose that will push on to the hot tap and the cold tap, linking them together. Some cheap hardware shops sell push-on rubber shower/hairwash sets that can be adapted. You can also get push-on tap adaptors intended for a garden hose. You just need a hose a couple of feet long to bridge between the hot tap and the cold.

If you have a hot and a cold washing-machine tap, these have screw-on connectors and you can fit a screw-on washing machine hose between them. they are only a few pounds in hardware shops.


Then turn turn on the hot tap, fully, and slowly open the cold tap. The mains pressure cold will push its way along the hose, into the tap, and "backwards" up the hot water pipes until it emerges into the tank.

This method will push out airlocks and may push out loose sediment.

the pressure might push the hoses off, so beware of water squirting over you.

 

[sra]

Thanks i will keep you posted.