Plug Cock

[Bon]

I have a plug cock fitted to the drain of my hot water cylinder.

When I've undone the nut the lever spins through 360 deg, not just the 90 or quarter turn I was expecting.

The water coming out of the drain pipe is very slow and if I lift the spindle at the bottom of the valve water leaks out from the seals of the plug.

Turning the valve seems to have no effect on the flow of the water.

I'm guessing it's had its day or am I doing something wrong?

 

[gas4you]

probably full of scale and partially blocked

 

[Bon]

Thanks for the quick response!

Would you recommend cutting it out and replacing with a modern-type drain-cock then?

 

[gas4you]

It is always best to have a drain cock that actually works

Wondering if your cylinder will be scaled up at the bottom as well though

 

[Bon]

I don't think it will be.

The drain point runs from the same point that the cold feed enters the base of the cylinder, i.e. the CF drops to low-level and then tees off into 2 directions.

One direction runs into the base of the cylinder and the other runs through the plug cock and picks up the CH F&E tank over-flow before running outside.

I have no problems with flow to my hot taps which would suggest water is flowing freely through the cylinder??

 

[ChrisR]

Plug cocks are far better than the 37p drain cocks which we all find done up with stillsons so the washer's come off or gone, and they don't work

You need a skewer and a bit of garden hose about 6" long.
Put hose on drain cock, bung it or fold over the end.
Open cock.
Pierce hose wall with skewer and thrust into cock, through and beyond if poss. Pull skewer back, close cock, remove hose and hope it works.

 

[Bon]

OK I'll try that.

But what about the fact that water leaks out of the top of the plug cock when it's open and I push the nut at the bottom upwards? To me that would suggest it's had it. Or have I undone the nut too far in an attempt to get water out because it's scaled up?

You'll have to excuse my ignorance to these things, I'd never even heard of them before

 

[ChrisR]

Normal drain cocks often leak too!
The tapered design of the PC does mean it can leak when you lift the cone shaped centre part out. If they're greased and adjusted just right they don't leak. I like them, it's a positive advantage to be able to undo the nut and get them unseized, and there's no washer to wear out or get abused.
You shouldn't need to actually lift the centre, sounds like the ole's bunged up.

 

[Bon]

OK ChrisR, thanks for the advice.

I'll try giving the valve a poke with a skewer of some description. Will be tricky as the drain runs outside but I'll not be beaten!!

Thanks again