Water Shutoff Knob Won't Turn

Forgive me in advance for mangling the plumbing terminology.

I am trying to replace the guts in one of my Mom's toilets. Her home was built in 1980. The water supply line turn-on/shut-off valve knob will NOT turn. It is currently turned all the way ON (all the way open) and when I started, I could see the valve threads covered in white corrosion. I brushed it off with an old toothbrush and then wrapped the pipe in a rag sopping wet with vinegar. I slipped some newspaper on the floor and left the vinegar rag there for a week to do its job. Well, I still can't hand-turn the knob. It is tight as can be and won't budge. I can't repair the toilet because I can't turn off the water. (I'm also concerned what we would do if we had a leak since I can't turn off the water supply!) What is the best way to loosen the knob? Can I use a wrench or do I risk causing a real mess? I CAN shut off the water to the house before trying - I know where that is and how to do it. Is there some kind of penetrating grease or lubricant that you guys use? A good tool? I appreciate any help or advice.

You know, I read one time that you should close and re-open every valve in the house once a year, just to keep the knobs "moveable". (Including all the ones for every toilet and both hot/cold water under every sink.) Now I believe it! I tried several others in Mom's house and most all of them are frozen tight!

Please help.

Thanks!
Carol

You will have to shut off the water at the main.

It would be a good idea to replace the shutoff.
Not an easy job for a homeowner though.
Even a lot of plumbers don't like doing it.

If it's copper pipe coming from the wall, I like to use a sleeve puller to pull the nut and sleeve off.
That way I can replace the escheon behind. 1/4" valves are the best.

If you loosen the bonnet nut on the shutoff, it may allow you to open the shutoff at the wall, but then it may leak afterward too.

Terry,

Thanks for your help! If I shut off at main, but DON'T want to start by replacing the shutoff, what is the best way to get the CURRENT shutoff knob to turn? Is there any way to do THAT?

Thanks again!
Carol

If you loosen the bonnet nut on the shutoff, it may allow you to open the shutoff at the wall, but then it may leak afterward too.

Well, I just got the knob to turn and now the shutoff leaks when the valve is open (water on). The only way to stop the leak is to turn the shutoff all the way off. Is there anything I can do now besides call a professional? Does that little screw that holds the knob on do anything? Should I leave well-enough alone?

The screw in the center of the handle just holds the knob on the shaft.

How is the valve attached to the pipe? Can you take a picture and post it?

If it is a compression fitting, you can probably replace it. If it is threaded onto a nipple, trying to unscrew it is likely to disturb the other end in the wall. That could be a pain, especially if the pipe moves. You'd have to take that nipple out to apply some new pipe dope or the connection in the wall will leak.

If it is soldered on, that, while not technically hard, takes some skill and tools.

Try Again

I can't tell if that is soldered on or not, but I think it is.

It looks like you almost have enough stub sticking out where you could just cut the pipe off on the wall side of the coupling and fit a new compression valve on what's left of the stub. If you unsoldered the coupling, there for sure would be enough.

I'd be very much surprised to find the valve is soldered onto the stub. What I think is that either this is a replacement valve or the original stub was cut too short and that is why the soldered coupling is in place.

What I would do is unsolder the coupling and replace it with a threaded adapter and then use a threaded valve. This would allow easy replacement in the future if necessary.

That is a compression stop.
If you get a new stop, you can unthread it and use the old nut and sleeve.

If we were doing the job, we would cut it behind the coupling and use a compression shutoff closer to the wall.

Thanks, guys! I'm headed to the plumbing store this morning to get a compression stop. I hope nothing here is soldered because I wouldn't know how to cut pipe or solder anything. Threading, I think I can do! I wish I knew exactly which of the parts in the photo is nut and sleeve - I see two things that look like a nut to me (maybe three if I look in the mirror) - but hopefully the plumbing store guy can tell me. I will let you know how it goes!

Carol

It will be easier to understand with the new one in your hand. You'll need two wrenches...one to hold the body of the valve and the second one to loosen the nut behind it. With all of the corrosion on there, it might take a lot to crack it free, but once you do, it should come apart.

It would look nicer if you can get the old nut and ferrule off and replace with new, but you may not be able to without a puller. The new valve should be able to use the existing parts left on the pipe.

Got it fixed! Stopped at the local plumbing supply this morning and bought a new compression shut off. Showed the guy my photos. He had the part and showed me how I might be able to remove just that round-top nut closest to the handle. Part cost $6. Came home and it worked! That round nut by the handle came off like butter! Screwed in the new part and worked like a champ! I NEVER, EVER thought it would be this easy - in fact I was sure I would be calling a plumber before the day was over.

Went on to replace the toilet fill valve and a short while later, I was all done! Totally amazing. I was due for something to go my way! Who would have thought I would have this done in a couple of hours for only six bucks?!

Terry, thanks SO much for this website and thanks to all of you who helped me!

-Carol

Sudden thought - is what I did ok?

-Carol

You replaced some of the parts. That was fine.
And you were lucky.

Most of the time, we just replace things, we need to have a guarantee on our work, and we don't like to jeopardize it for a few bucks.

If it works, it works.