overflow from loft leaking

[skipper]

I am having a problem with the overflow dripping all the time from my water tank in the loft! its definately not the ball cock that needs adjusting and i cant see any water dripping from anywhere but the plastic tank (think its called the expansion tank) keeps on filling up! Any ideas would be appreciated as i would like to know whats wrong before i pjone a plumber! Thanks

 

[oilman]

It could be a leak from the hot water tank into the heating system through the coil in the tank.

Is the level in the cold water tank higher than the level in the expansion tank?

 

[skipper]

Not sure really but i emptied the expansion tank down to a level where it wasn't dripping from the overflow and the water was warm. By the way the overflow drips when heating is on and of, don't know whether this matters as i am pretty clueless when it comes to plumbing.

 

[oilman]

Leave the expansion tank full, is the level in the cold water tank higher?

 

[skipper]

I will have to check that later as it takes a few hours to fill up and start dripping again after i have emptied it. J ust to be certain does the cold water tank sit on top of the hot water tank and have an overflow which takes the water from there to the expansion tank?

 

[oilman]

It would depend on your installation, but you haven't said much about it. The overflows should go straight out of the building, not into another tank.

 

[peter anderson]

I think we're confused about tanks. Is the big tank or the little tank overflowing?

 

[skipper]

Sorry for being vague, as i said i am clueless!
In the loft i have a copper tank but it looks like 1 small tank on top of a larger tank. From the small tank on top there is a pipe which i think is a sort of overflow pipe which leads into a black plastic tank which i think is the expansion tank. This tank has an overflow pipe which leads outside.
Water seems to be dripping from the small copper tank into the black plastic tank and consequently filling until it starts dripping outside.
I have tried turning the pump down but with no luck, as i was told this might be the problem.
Hope this gives you some idea of what i am talking about.

 

[oilman]

Where do the other pipes that come out of the tanks go to?

 

[skipper]

Sorry for the delay in getting back!
Just been in the loft and had a look inside the small copper tank, it has a ball valve inside and the water level is above that and dripping into the expansion tank!
I didn't raelise that the small copper tank had a ball valve inside, could this be the problem and if so is it easy to fix? i have just been looking at the ball valve inside the expansion tank.

 

[peter anderson]

if you don't know how to fix it its best to get a plumber in because you could end up with water spurting everywhere

 

[skipper]

Just been back in the loft and emptied the small copper tank down to its normal level and there is a trickle of water coming from the end of the ball valve! It looks like that is the problem. Thanks anyway!