water not coming from tank(getting hot though)

[brij]

hello
I've an independent water heating tank which works with the immersion heater. it is not linked to any boiler.Since saturday night the hot water has stopped coming from the hot water tap. You get 2 glass full of hot water every 10 minutes or so and then it stops. The water is getting hot but just not coming in the taps apart from the 2 glass full every 10 mins or so. it is the same in kitchen and bathroom.there seems to be a bust of air before the 2 glass fulls come out.
Any suggestions/ideas will be welcome.
regards

Brij

 

[Dan Robinson]

Search the forum for how to deal with airlocks.

Make sure the cold water tank in the loft is full of water too.

 

[Space cat]

Agreed. The first place to look is the cold water tank that feeds your hot tank. If that's empty (or nearly so) you won't get much out of your hot taps.

Airlocks can be tricky things to sort out but they happen all too easily if the pipework has been fitted badly. All it takes is a slight upward slope in any part of the pipe that runs from the bottom of the cold tank to the bottom of the hot cylinder (the cold feed).

 

[brij]

thanks alot.Will get home today and try it.
did check the loft tank yesterday. Quite full and tried pushing the ball up and down and it seemed ok.
Cheers

 

[Space cat]

did check the loft tank yesterday. Quite full and tried pushing the ball up and down and it seemed ok.

Another possibility is a partial blockage in the cold feed pipe. Can you get more than a couple of glasses out if you wait longer between attempts?

 

[brij]

no not really...the 2 glasses limit seems to be the same even though u wait for about 45min-1hr.

 

[Nige F]

double post

 

[Nige F]

thanks alot.Will get home today and try it.
did check the loft tank yesterday. Quite full and tried pushing the ball up and down and it seemed ok.
Cheers

Did it have a lid / cover on it ? - If not you`ve probably got a rat`s skull down the pipe - seen that one myself

 

[Space cat]

A blockage could be the cause but only if the take-off point for all the hot taps is high up on the vent pipe; so high in fact that the water above it up to the level in the tank would only fill two glasses. Is this the case?

 

[brij]

had one hour checking everything and finally decided to call a plumber in...
tried taking the water out of the tank but guess what??the screw for the water outlet wouldnt budge after trying everything...if would try too hard there was a danger of the tank breaking!!
put some thin tubes from the immersion end and took quite abit water out...kept the hot water taps open and refilled the tank with water but same prob again...
any ideas on what to do next!! spent 3 hours after work with no avail!!HELP!!

 

[stardanny]

Hi.

You say you tried to unscrew the top connector of the hot water tank but couldn't? Sound like there is limescale inside outlet fitting, narrowing flow of water.

Is the cold feed gatevalve to cylinder fully open? Are you sure it's open?

Dan.

 

[Space cat]

I can't see this being a blockage problem. Contrary to what I said three posts ago, the take off point for the taps doesn't really matter. A partial blockage would allow water to fill the vent pipe all the way up to the cold tank water level if you left it long enough. Opening a tap would then allow all the water in the pipework above that tap to run straight out and that would surely fill more than two glasses.

I think you'll find that you have an airlock in the cold feed pipe. All it needs is for some section of the pipework to rise by more than the diameter of the pipe. Take a close look. You might find a spirit level useful.

 

[brij]

thanks for all your kind advice guys!!
had to call another plumber in..it was an airlock in the tank and as it is a old copper tank, there was a risk of breaking by trying too hard..
the chap put in a pipe from the cold water inlet pipe and manually blew air into it..
prob sorted!!