Overflow Leaking

[concretpump]

I put in a new combination cylinder in my daughters flat about three years ago, but it now keeps on leaking from the overflow pipe.

I have put in 2 gate valves 22m and get her to turn off every day and turn off elec, but cant find out why it sends water into the header tank. When the mains feed is off it does not leak.

Any suggestions.

 

[YELLERBELLY]

your post makes no sense

 

[concretpump]

your post makes no sense

i have put two 22m taps on the cold feed which go into the tank the taps are there so my daugther can turn off water as it is pushing water into header tank and leeking once they are turned off it wont leek but for some reason water is going into header tank and leeking

 

[jackecole]

so you put in an open vented combi boiler?

what's the water level in the hedaer tank when system is cold?

 

[concretpump]

i have droped the level by 4 inchs she is on the third floor , can find any thing else that would make water go into header tank

 

[jackecole]

you def have a combi boiler? no hot water cylinder?

other things could be plate heat exchanger pinholed and causing mains water to force primary water up through tank and out of overflow....

 

[concretpump]

if you mean combi boiler, by combination cylinder then yes thats what it is , i only changed like for like when they moved in pipe go on out side of cylinder but is covered in foam