How so I unstick a stuck stopcock?

My (water) stopcock is stuck. It’s in an awkward position (at arm’s length under the bath!) and turns all of approx 10 degrees and that’s it. I’ve tried applying penetrating oil without success. So how do I unstick it?

Only suggestion I can make is to keep working it back and forth. You want to avoid too much force, I’m guessing you’d have a serious problem, if you broke it.


At least you’re not crimping butt connectors onto a thrust regulator…

If you’re attempting to close it so other work can be done, it isn’t likely to bear fruit. Valves are so seldom used and with the passage of time, the stop washer deteriorates so it won’t effectively close, anyway.

Rehabbing a bad valve (for disassembly or freeing) can sometimes be done with heat, as in a torch, but if any parts of the valve are plastic, a disaster will result, as can happen when torches are improperly handled.

A wrench or vise grips can do the trick. If you plan on doing any plumbing you should replace it. Gate valves eventualy just stop working. Whenever you put in new plumbing use ball valves they are far more reliable.

Quartz says it’s a stopcock and mentions it only moving 10 degrees, so I’m assuming it’s a ballcock. Sometimes, if they haven’t been operated in a long time, they will build up a ridge of calcium or rust, working it back and forth may wear this away and allow the ball to turn. If it’s a gate valve, or globe valve, they present other problems when not operated for long periods. It would probably be best to turn off the water and repair or replace it, but Quartz also said it was behind the tub, so it’s probably going to be expensive to do either.


What I may do then is leave it stuck open and have another stopcock fitted somewhere more accessible.

When I was a student I had a summer job working at an NZ university. We were removing 4 inch galvanised gas pipes from the service tunnels. The “tool of choice” for the job was a sledgehammer to break the pipe joints. During this process, the 10inch water main just below the gas pipe was damaged, and started leaking (the pipe was some sort of fibrous construction, so it bruised and did not crack or break - which would have killed us all). We were in a whole heap of trouble.

Anyhow, they layed on a replacement section of pipe, got a crane to drop it into the tunnel, and then tried to isolate that section by closing the valves. After trying to drain the isolated section for about an hour, it became obvious that the valves did nothing to close off the flow through the pipe, and the spotlight of accusation shifted off us and on to the permanent plumbing team, who had obviously neglected to service the valves over a period of years. They put a temporary patch on the leak, left the new pipe in the tunnel, and probably put the whole thing on the too hard pile.

The moral of the story - valves need to be serviced - says me thinking of all the little isolation valves in the house that I have not looked at in 5 years. I hate plumbing. :frowning:


This may be the dirtiest thread I’ve ever read. Maybe I’ve been missing out by not doing my own plumbing.

Say that five times fast.

Are you in the UK and is it the first stop cock in the property?

If it is, it is the water company’s responsibility, they will fix it free.
Otherwise turn the water of using the cock outside the house and fit a more easily accessible repacement. Push fit valves are simplicity itself to fit.

A plumber’s job is a dirty one when repairing water supply lines. :smiley:
The real dirty work is on the drainage and sewerage systems. :rolleyes:
Not for the squeamish nor faint at heart. :eek: