Feeder tank overflowing

[Andre Louw]

HELP! The overflow pipe was dripping a lot. After cleaning / descaling, and then replacing the ball valve in the central heating (open vented) feeder tank, the problem was not solved. Still dripping a lot. The only other pipe connected to my tank is the pipe that feeds the heating system. I have blocked this off, and the dripping has stopped.
It seems to me that there I some sort of "back pressure" feeding water into the feeder tank. Is this possible in an open vented system? How can I solve this?
The heating is off.
I have bled all radiators.
Advice appreciated.

 

[rpm]

That is possible, I`m sure somebody will be along later around 6 - 7 pm to advise you but you might need a qualifed person as it may not be a DIY job if it is pressure related.

 

[Rickster123]

What exactly have you blocked off??

 

[rpm]

Good point AP, didn`t think about that. Could there be a pressure bomb about to go off? Hopefully there`s a PRV?

 

[mutley racers]

Sounds like he blocked of the feed to heating system!

Op, any dirty water in hot? Sounds like it could be a split coil. Is the small tank higher than the big tank?

 

[mutley racers]

Good point AP, didn`t think about that. Could there be a pressure bomb about to go off? Hopefully there`s a PRV?

No Prv on that feller. That's what the f&e is for

 

[rpm]

Thanks, everyday is a skool day

 

[GasmanxxxR1]

In my experience with a split coil the water goes that 'minty' green in the F&E tank, anyone else notice that?

 

[WHPES]

Do not delay sorting it or your radiators and boiler will rapidly corrode away!

 

[Riley]

Nothing from OP but does sound like split coil