So what if the ballcock on the F&E tank doesn't work...

I recently noticed a dripping from what I assumed to be the overflow form my Boilermate II. I (mostly) emptied the F&E tank, gave it a wipe down and then realised the whole time the ballcock hadn't been trying to refill the water. On closer inspection it looks like I have previously (and I'm talking numbers of years ago) turned the screw that feeds this pipe so that it is off... and wrapped a load of plumbers tape around it in a bit of a bodge. When I turn it back on I remember that I couldn't get it to stop dripping without it being off! Water initially sprays out of the screw in small jets but doesn't flow into the F&E tank. I try once more and the water drips out of the screw but still only drips into the F&E tank.

• Is it possible to turn off the feed from the ballcock (i.e. is that what I have done)?
  

• What problems could this cause (as it's been like that for years and I've not noticed any)?
  

• If it is to be turned back on, (and I assume it should be) how do I stop water dripping from the flow control screw?
  

• What would cause it to be in a 'on' position and only drip water into the F&E tank?
  

Sounds like you have a 15 mm isolating valve? Turn on and off with a slotted screw driver?
If so replace it.
And the ball valve.
Peglar part 2 with a brass pin is best.
Your BM II and the boiler / system is filled via the F& E tank.
You need to get it sorted.
Mike

I forgot to say thanks for the quick and helpful response.

Thank you very much!