Do you have a bucket or cup under your shut off valve because it is dripping? I know how frustrating that can be.
What you may not know is that fixing a leaking shut off valve is incredibly easy and you will rarely need to pay a plumber to it for you or replace the valve.
The reason your shut off valve is dripping/leaking is because the washer inside has hardened over time, or it is covered by mineral deposits. Since these valves are rarely operated, when you close the valve then open it the washer will fail to seal properly and hence the dripping.
A loose packing nut may also cause your shut off valve to leak. The function of the packing nut (also known as bonnet nut) is to compress the washer on the valve stem thereby creating a watertight seal.
As water flows through the valve, the water pressure creates vibrations through the valve which causes the packing nut to loosen. The loosening process is a slow and gradual and that is why the leak starts off as a slow drip before it develops in to a severe leak if not fixed in good time.
Gate valves (operated using a knob) fail/leak at a higher rate compared to ball valves (operated using a lever). If you can, replacing a gate valve with a ball valve is a smart decision.
To fix a dripping/leaking shut off valve, use an adjustable wrench to tighten the packing nut which will compress the washer and stop the leak. If that does not work, loosen the packing nut and wrap Teflon packing around the valve’s bonnet threads. Tighten the packing nut and check if the leak stops.
Unfortunately, some leaking shut off valves will need to be replaced. You may even choose to replace your shut off valve immediately you notice it leaking as it is the best and long-term solution to the problem.
Shut off valves cost between $10 and $30. A plumber will however charge you between $150 and $200 to replace the valve for you depending on your location and the scope of work.
How to Fix a Leaking Shut Off Valve
There are 3 methods you can use to fix a leaking/dripping shut off valve. I will start with the easiest and fastest of them all and then we will look at the others in order of ease of repair.
You will need the following items for this job:
- Adjustable wrench
- Teflon packing (optional)
- Shut off valve washer (optional)
- Screwdriver (optional)
The following are the 3 ways to fix a dripping shut off valve:
1. Tighten the Packing Nut
This is the best method to fix a leaking shut off valve without turning off the water.
A dripping shut off valve can be easily fixed by just tightening the packing/bonnet nut. This is the nut that is just below/next to the valve’s handle/knob.
Grab an adjustable wrench or slip-joint pliers and gently tighten the valve’s packing nut. Since the nut will not be very loose, this will involve turning it by about 1/8 or 1/4 of a turn clockwise.
Check if the dripping stops. If indeed the dripping stops then that is the end of the job for you.
2. Wrap Teflon Packing around the Valve Spindle
Teflon packing isn’t the same as Teflon tape, although the later can be used in the absence of the former although not ideal.
If tightening the packing nut does not stop the leak, you will need to wrap Teflon packing around the spindle threads of the valve to help it create a watertight seal. Here is how to go about it:
- Turn off water supply to the dripping valve. You house’s main shut off valve is located in the basement near the water heater or on an external wall where the main water line enters the house. If it is the main shut off valve that is leaking, you will need to turn off water from the water meter shut off valve near the street.
- Drain water from the pipes by turning on a faucet.
- Use a wrench or slip-joint pliers to loosen the packing nut.
- Pull the packing nut all the way back to expose the threads of the valve’s spindle.
- Apply about 3 wraps of Teflon tape on the spindle threads.
- Screw in the packing nut until just hand-tight.
- Gently tighten the packing nut using a wrench or pliers but not crazy tight.
- Turn on water to the valve back on.
- Open the valve slowly and check if the leaking has stopped.
3. Replace the Packing Washer
If you have tried the above 2 methods but still your shut off valve is leaking, the packing washer is completely worn out and replacing it is the only viable solution.
You can buy a packing washer from your nearest plumbing store. You may want to take a picture of the shut off valve so that the store can give you the correct washer. These washers are really cheap and fast to replace compared to replacing the entire valve.
Once you have bought the packing washer, this is how to proceed:
- Turn off water to the valve and open a faucet to drain water from the pipes. I always avoid draining the water heater since an empty tank will cause the element to burn. Unless you turn off the power to the heater prior.
- The valve handle is connected to the valve stem using a screw. Use a screwdriver to remove the screw.
- Once the screw is out pull out the handle.
- Loosen and remove the packing nut using a wrench or slip joint pliers.
- Slide out the old packing washer.
- If the valve stem is corroded, scrub off the corrosions and mineral deposits using an emery cloth.
- Slide in the new washer.
- Screw in the packing nut until just hand-tight then tighten it further with the wrench but do not overtighten it.
- Use the screwdriver to attach the valve handle using the screw.
- Turn on the water supply to the house back on.
- Slowly open the shut off valve and check if the dripping/leaking has stopped.
And basically that is how to fix a dripping/leaking shut off valve.
If everything else fails, you can always replace the shut off valve. Replacing a shut off valve is not an easy task and you will need to hire a licensed plumber, unless you are an experienced DIYer.
Here is a great video on how to replace a leaking shut off valve.