Drip from ballcock (not the spout)

[Alfie25]

I've had a new ballcock fitted and have noticed that water comes out of not only the white spout/nozzle, but also a drip from underneath the knurled brass ring at the front of the valve (where the arm attaches to). Surely this isn't meant to happen?

Is there any way this can be tightened up or is it a duff part?

 

[Elkato531]

Hold up the arm so that the valve is closed. Is water still dripping from the front? If not then its most likely OK. The point where the spout screws in is not a water tight seal so a bit is probably escaping from there and dripping off the valve body.

 

[Alfie25]

When the tank is filling up, I'd say almost as much water comes out of this part as the white spout! After the spout has stopped dripping, water continues to drip out of the bottom of this knurled section. Lifting the arm up does seem to stop the drip, or at least slow it to hardly anything.

When I release the arm again, the drip starts again, quite slowly, and I imagine it could take a long long time to raise the float enough to shut it off completely.

 

[Alfie25]

I think the leak is on the threads of the large nut (that the float arm is attached to). Should these be watertight? If so, how? I believe it's just a screw fit. I've checked it and it's tight.

 

[Elkato531]

That large nut compresses the float arm carrier against the diaphragm washer. It may be that the washer is not seated correctly within the valve. Take it apart, put a new washer in and that should do it. Or just change the whole valve, they're only a few quid.

 

[Alfie25]

On closer inspection you were right first time. It's not actually the big nut that's leaking - it's from where the white spout pushes/screws in. The water is coming up through the threads then dripping down off the lowest point of the valve body. The old valve never had this problem so I'll put it down to cheap parts on this one. Thanks for your advice.