Overflow From Tank

BlackEdelweiss

We live in a rental house. There is a pipe running from the large tank in our attic directly to outside just under the rafters. This pipe had an almost continuous flow of water running from it. It does stop sometimes but is on more than off from what we can see.
The landlord sent a plumber around and he said he sorted the issue but it is still flowing out.

Is this something that needs to be sorted out or is it harmless? Could it be costing us money from oil or electric use?

It also flows right into the alley at the side of the house where we keep our bins and it makes it hard to get to them when putting them out for collection.

Muahahaha

Had that problem before in an apartment. If the water is still flowing then the plumber hasnt sorted it. In my case it was a faulty ball cock in the tank that was no longer stopping the flow of water into the tank when it was full as it should do. Got a new one in a DIY shop and switched it out and the problem went away. You could check yours first and see is the arm functioning properly or is there something making it stick.

Shouldnt be costing you money as it is likely a cold water storage tank but if left flowing for weeks on end it could cause water damage outside the house. It definitely needs to be sorted though.