Your house has a main water shut off valve that turns on and off water to the whole house. There are also other shut off valves to turn off water to specific fixtures.
These are the shut off valves you see under the kitchen and bathroom sink, on the wall behind the toilet, behind the washing machine and on outside spigots. Showers may or may not have shut off valves.
Whenever you need to carry out plumbing repairs, you must first turn off water to the fixture or sometimes the whole house. If the shut off valve has not been operated in a long time, you will find out that it is stuck and will just not turn.
Stuck shut off valves are caused my corrosions and mineral deposits either on the inside or outside the valve making it hard to turn the valve shaft. Turning all your shut off valves on and off at least twice a year is a good way to prevent them from getting stuck.
To loosen a stuck shut off valve, loosen its packing nut then try to turn the handle left and right. If that doesn’t work, spray it with a penetrating oil and wait for a few hours. Blowing hot air over the valve using a hairdryer is also another great way to melt the gunk and loosen it.
Although WD-40 is not a penetrating oil, it is very effective in loosen stuck shut off valves. Spray WD-40 around the shaft of the valve and give it time to loosen the bond between the rust/corrosion and the metal surface.
When dealing with a stuck shut off valve, you need to be patient. Don’t pick a hammer and wrench and force the valve to turn off by hook and crook. You will end up breaking the valve or the water pipe.
4 Ways to Loosen a Stuck Shut off Valve
There are several methods you can use to loosen a stuck shut off valve. Some will work on your valve while other will not, based on what it is causing it to stick as well as the severity of the problem.
Needless to say, these are trial and error methods so you may end trying all of them. You will therefore need a lot of patience.
Before starting the job, I would recommend that your first start by turning off water to the valve you are working on. This may involve turning off water at the main house shut off valve, unless it is the one you are trying to loosen.
Your house’s main water shut off valve is located where the main water line from the street enters the house. This could be on an external wall or inside the house in the basement, garage, crawlspace or utility room. It is always very near to the water heater.
When you turn off the water to the valve, drain the water already in the pipe to release the pressure.
And now here are the 4 methods you can use to loosen a stuck shut off valve:
1. Twist the Valve Right and Left
This method may look too obvious but you may be surprised at how well it works at times. Grab the valve’s handle/knob with your bare hand and start to play with it by attempting to twist it clockwise and counterclockwise.
You may need a cloth or gloves to help you twist the knob with ease.
After a few seconds, you will notice that the valve starts to free up and turning it will be easier. Keep playing with it until it loosens completely.
If this does not work, don’t force it by using leverage. Proceed to the other methods.
2. Loosen the Packing Nut
If you look below/next to the valve knob/handle you will see a nut which connects it to the valve body. That valve is called a packing nut or a bonnet nut.
Loosening the packing can loosen the shut off valve as well. Before grabbing a wrench, place a small pan/bucket under the valve to collect any water that may spill once the nut is loosened.
Grab the packing nut with an adjustable wrench and gently turn it 1/4 turn counterclockwise. Now grab the valve handle and try to turn it back and forth until the valve loosens up completely.
Once the valve is unstuck tighten the packing nut to avoid leaks. Proceed to the other methods if this one also fails to loosen it.
3. Spray Penetrating Oil on the Valve
A penetrating oil is a type of oil with low viscosity (resistance to flow) which allows it to penetrate/seep through a connection thereby lubricating and loosening it. Kroil, PB B’laster, Liquid Wrench and Knock’er Loose Plus are all decent penetrating oils to buy.
Check them out here on Amazon.
WD-40 is not a penetrating oil but it will do the job. Apart from breaking the corrosion bonds, it will also prevent further corrosion in the valve.
Start by loosening the valve’s packing nut all the way. Once loose, lift off the packing nut and spray the penetrating oil around the valve’s stem. Give it about 2/3 hours to penetrate through the valve.
You can also periodically add more of the oil on the valve since most of it will drip on the floor anyway. This methods works especially well in shut off valves that are upright as gravity comes in to help.
After a few hours, use a hammer or wrench to gently tap on the valve to help unstuck it. Alternatively you can grab the valve handle with a wrench and use a hammer to gently tap the wrench in a counterclockwise direction.
4. Blow Hot Air on the Valve using a Hair Dryer
I should start by saying that this method will only work if you are try to loosen a stuck cold water shut off valve. It will not work on hot water shut off valves.
As I had mentioned before, the shut off valve is stuck due to mineral deposits embedding on it. Blowing hot air over it using a hair dryer can melt the gunk inside the valve making it easy to turn on and off.
You need to have a electrical outlet close to where the valve is located. Plug in the hairdryer and adjust it to the highest heat settings.
Turn on the hairdryer and blow hot air all over the valve for 5 to 10 minutes. Check if the valve has loosened.
If using a hairdryer is not viable, boil some water until it starts steaming. Pour it in a bowl (plastic of course) and soak in a heavy cloth/towel. Place the cloth over the valve and wait for a few minutes.
You can as well pour boiling water over the cloth slowly with another container underneath it to collect the water. Check if the valve has loosened.
Gently tap the valve with a hammer as you turn the knob at the same time and see if that works.
And that is how to loosen a stuck water shut off valve. If all these methods don’t work, you can call in a plumber to help you fix it. Plumbers have dealt with stuck pipes plenty of pipes and know exactly what needs to be done to loosen it.