How to Replace a Leaking Toilet Shut off Valve

A toilet shut off valve is locate on the wall behind the toilet. It gives you a means of turning off the water to the toilet when you need to carry out repairs and maintenance on the toilet instead of turning off water to the entire house.

Today I will show you how to replace a leaking toilet shut off valve. This is an easy task which you should finish in under one hour depending on your experience level.

A water supply line is usually connected from the shut off valve to the toilet tank. It is always a good idea to replace the supply line as you replace the shut off valve. A supply line is inexpensive and saves you the time of having to replace it in the near future.

Toilet shut off valves are rarely used and as a result normally get stuck. When you finally force them to close, you may notice that they will start to leak.

The shut off valve contains a rubber washer which creates a watertight seal and preventing any leaks. With time, the rubber washer deteriorates and this is the main reason shut off valves leaks. You might also hear a vibrating sound after each flush as the tank refills.

The vibration is caused by the rubber washer moving about the valve as the water flows out. You will also notice that after the tank is full the vibration stops.

Although repairing the shut off washer is possible, replacing the entire valve is the long term and better repair.

Related: How to replace a toilet fill valve.

Types of Shut off Valves

Prior to replacing a toilet shut off valve you will first need to know the type of valve you have. There are basically 3 types of valves:

  1. Compression valve – This is the type of valve that is neither soldered nor threaded to the pipe. It uses a brass compression ring which is deformed using a nut to make it tight. This is type of valve you you should use.
  2. Threaded valve – This type of valve is threaded straight on the pipe. Compression valves are used on copper pipes but threaded valves are mostly used with iron pipes.
  3. Sweat valve – Sweat valves are normally soldered on the pipe. They have a slightly larger diameter than the pipe which is filled with hot solder which sticks it to the pipe. Replacing a sweat shut off valve you need a solder torch and you also need to have a fire extinguisher on stand-by. If you are not comfortable replacing this type of valve you should go ahead and call a plumber.

How to Replace a Leaking Shut off Valve

how-to-replace-a-toilet-shut-off-valve

The first thing you should do is to gather all the tools and materials necessary for the job, depending on the type of valve you are replacing. These are the items needed:

  • 2 adjustable wrenches
  • Sponge
  • Soldering torch
  • Flame protector
  • Fire extinguisher
  • Leather groves
  • Emery cloth
  • Penetrating oil (optional)

Step 1: Buy the right valve

The good thing is that shut off valves are universal so you really don’t have to worry about the size. It is the type you need to focus on.

A ¼ turn ball valve is the kind of shut off valve you need to buy. It is easy to install, does not jam/lock and does not leak. If you have a sweat valve, consider replacing it with a compression valve. If your pipe is threaded you will need to make sure you buy a threaded shut off valve too.

Step 2: Drain all the water

  • Turn off the main shut off valve to the house. You will most likely find this valve in the basement next to the heater or adjacent to the water meter. If it is a wheel valve turn in all the way clockwise but if it is a butterfly valve turn it 90 degrees (perpendicular to the pipe)
  • Turn on any of the faucets in the house to drain the water already in the pipes.
  • Flush the toilet and hold the handle down to remove as much water as possible.
  • Remove the toilet tank lid and place it in a safe place.
  • Use the sponge to soak up the water still left at the bottom of the tank.

Step 3: Disconnect the Supply line

how-to-replace-toilet-shut-off-valve
  • The supply line is connected to the toilet tank using a plastic coupling. Loosen the coupling with your hand since it’s normally hand tight. Use a wrench only if it is too tight. Put a small bucket or towel on the floor to catch any water that might drip on the floor.
  • Use a wrench to disconnect the supply line from the shut off valve by turning the connecting nut counterclockwise.

Step 3: How to Remove and Replace a Compression Shut off Valve

  • Here you want to turn the compression nut and not the valve itself. Back off the valve with a wrench and use the other wrench to turn the nut clockwise. Pull out the valve.
  • The compression ring and nut will still be left on the pipe. Use a wrench or pliers to grab the ring and pull it out of the pipe. Do not use too much force which can oval and deform the pipe.
  • If the ring is too tight on the pipe, use a hacksaw to cut it off. Knock it out and remove the nut too.
  • Push the new compression nut and ring into the pipe. If the previous ring left a dent on the pipe position the new one away from the dent.
  • Now slide the valve into the pipe and compress the ring on the valve using the nut by hand tightening it until snug. Use a wrench to back off on the valve and use another wrench to turn the nut counterclockwise until it’s tight. Make sure the valve is facing upwards to connect the supply line easily

Step 4: How to Remove and Replace a Threaded Valve

  • This valve is threading straight on the pipe. There is no nut on the pipe and you therefore risk leaving very ugly marks on the pipe. You also want to turn the valve and not the pipe so you should make sure it doesn’t turn.
  • Wrap a piece of emery cloth on the pipe and adjust a wrench to fit tight on it. Apart from preventing wrench marks, the emery cloth will help you have a tight grip. If you don’t have an emery cloth you should use a rag or duct-tape.
  • When the wrench is tight on the pipe drop its handle to the floor for support. Use the other wrench to turn the valve counterclockwise until it is loose.
  • If the valve is too tight, spray some penetrating oil on it and leave it for about 15 minutes.
  • Clean the pipe’s threads and apply Teflon tape.
  • Carefully hand tighten the valve on the pipe until its snug. Make sure it is well aligned. If it is not aligned don’t force it in otherwise you will strip the threads.
  • Use the 2 wrenches to tight it.

Step 5: How to Remove and Replace a Sweat Valve

  • Make sure you have the fire extinguisher by your side and remove any unnecessary material that could easily catch fire.
  • Stick the flame protector on the wall around the pipe. You do not want to mess with the wall finishing.
  • Remove the valve stem. Hold the valve body with one wrench and use the other wrench to loosen the packing nut. This will help you drain out all the water in the pipe which will make your work easier.
  • Hold the valve tight using pliers or the adjustable and rock it.
  • Put the torch on the smallest flame and aim it directly on the body of the valve. The solder will start to melt.
  • Using the pliers or wench, turn and pull the valve until it comes off the pipe.
  • Some solder will still be left on the pipe. Use the torch to melt it too. With you leather gloves on, wipe off the solder with a dump cotton rag.
  • Use an emery cloth to remove all the traces of solder from the pipe. This is important if you want to replace the valve with a compression valve.
  • Install the new compression shut off valve as indicated above.

Step 6: Connect the Water Supply Line

  • Connect the water supply line’s nut on the valve and hand tighten till snug. Use the wrench to tighten it further. Do not however tighten too much that you strip the threads.
  • Connect the supply to the toilet tank. Remember this connection should only be hand tight. Using a wrench could deform it.

Step 7: Open the Main water supply.

  • Go ahead and open the main house shut off valve.
  • Open one faucet and let the water run until all the air has come out. You will know this when the bubbling stops.
  • Turn on the toilet shut off valve and let the tank fill with water.
  • Keenly check for leaks on the new valve.
  • In case of any leaks tighten the valve a lit bit otherwise enjoy your new valve.

And that is how to replace a toilet shut off valve. The sweat shut off valve can be a little difficult to replace for some people but the threaded and compression shut off valves are a piece of cake.