Help needed on water tank issue.......

[BTez]

Hi

I've got an issue with my water tank where every now and then it overflows causing water to come out of the overflow pipe which then falls outside. I've had this issue for a number of years and it is very starange as I can't see where this excess water comes from.

My initial thought was that it was something to do with the ball cock on the tank itself which i have replaced, but to be honest everytime i've noticed that it's overflowing and have opened up the tank the ball cock seems fine and no water is coming out of it.

My next thought was that it was maybe the boiler overflow which was somehow overflowing and filling the tank which then led me to think that the hot water was too high or the thermometer on t he boiler was faulty. So to test this I made a make shift cup and attached to the overflow so I could at least if there was any water present in it once I noticed the tank had overflowed. However after doing this and checking the the cup was dry proving nothing had come from the boileroverflow.

So if my ball cock is working okay and isn't leaking and the boiler isn't overflowing how does the water get it to the tank to cause it to overflow???

Could water every come back up the pipes at the bottom of the tank and if so how?

Any advice would be appreciated.

Thanks

Dave

 

[AWheating]

water tank feeding the hot water cylinder or water tank feeding the heating system?

 

[BTez]

water tank feeding the hot water cylinder or water tank feeding the heating system?

I think the answer would be both......I have one water tank (plastic) at the top of my house and have one hot water cylinder which i'm not too sure what feeds it - but i would imagine the tank as when I notice the water dripping from the overflow I simply turn a tap on (any sink) and the water drains away and stops overflowing. Which is how I currently resolve the problem.

The central heating system is not on at the moment as the weather has still been mild enough to do without it.

 

[bigads28]

Do you have any mixer showers? If the cold is on the main but the hot is off the tank then you can the cold going up the hot pipe and filling the tank.

 

[BTez]

Do you have any mixer showers? If the cold is on the main but the hot is off the tank then you can the cold going up the hot pipe and filling the tank.

Thanks for the replies - yes I do have a couple of mixer showers but i'm not too sure what feeds what - why would it do it sporadically though? as it can go a couple of weeks without doing it and then it suddenly happens.

 

[josh]

Sounds like a faulty ball and cock to me.


if you turn a tap on and it resolves it and only does it now and again (presumably when you havn't run a tap for a while) would say to me its just the diaphragm washer. Nice easy one.