Usually a failed ball valve but could be other problems eg failed cylinder coil of backflow
Check to see if the ball valve is dripping
Ps. Assuming you are not referring to the discharge pipe from an unvented hot water cylinder. In which case the problem needs to be investigated by an engineer with unvented qualification
Which water tank is it? There could be two, one that stores water and the other for the central heating.
A dripping overflow pipe, could be down to the the ball valve not closing, this could be that it has seized, require new washer or that there is debris in it that will not allow the valve to close, also it could be that the float height requires adjusting.
Then there is always a chance that you have water expanding through the vent pipe, this would require a little more investigation.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local
