No Shut Off Valve Under Bathroom Sink: What You Can Do

You may not think you need a shut off valve under your bathroom sink, until you really, really do. Rather than waiting for disaster to strike, see if you have one now—before you need it.

If your bathroom doesn’t have a shut off valve, you need to put one in as soon as possible! Don’t make the same mistakes I did: get your plumbing sorted today.

Shut-Off Valves

Shut-off valves should be on both pipes under your bathroom sink. They are required in most areas to meet local code standards. If you purchased an existing structure without valves, installing new ones is recommended or may be required. 

The valve allows you to control the water flow in a specific location without turning off the main water flow to the entire house. 

Look at the pipes under the sink to locate the shut-off valves under the bathroom sink. The large tube is usually for drainage and may angle to the wall or descend into the crawlspace or basement beneath the house. 

The two small pipes supply hot and cold water to the sink. Each line should have an oval or football-shaped plastic or metal handle. The valve can be located anywhere on the line.

No Valves

If you do not find the valves under the sink, you will likely have to attach them. To connect shut-off valves to an existing line, you will have to shut off the water supply to the house.

There are usually three different places to look for valves.

  1. They are attached to the pipe near the meter.
  2. They are under or at the end of the home where the hose attaches to the supply.
  3. There may be one at the water heater.

Options

There are eight types of under-the-bathroom sink shut-off valves on the market at hardware stores. Installing one that is chrome-plated brass is the most cost-effective.

  1. The straight shut-off valve is for vertical supply lines.
  2. The angle stop valve is for perpendicular lines.
  3. The compression valve is for rigid copper lines without soldering.
  4. Copper sweat top valve for soldering directly to copper pipes.
  5. The iron pipe valve is for galvanized or brass threaded pipes.
  6. CVPC valve is for CVPC pipes.
  7. The PEX valve is for PEX pipes.
  8. The push-fit valve is for CVPC, PEX, or copper pipes.

Installation

To begin the installation process, turn off the water supply to the house. Next, turn the water on the upper and lower faucets to drain standing water. Draining the standing water will decrease the likelihood of leaks while installing new shut-off valves, so I suggest you have a bucket ready.

After opening the cabinet doors and looking at the pipes, determine what kind they are. Copper pipes are gold-colored metal. Galvanized pipes are gray. PVC pipes are white plastic. 

The type of pipe you have determines the kind of shut-off valve you will install.

Angle Stop Shut-off Valve for Perpendicular Line Installation

  1. Use a wrench to loosen the water supply tube. Break to nut loose with a twist and remove it with your fingers.
  2. Disconnect the other end from the underside of the sink.
  3. Unthread the old adapter from the sink and remove any debris.
  4. Brush on a coat of pipe-joint compound.
  5. Thread on the new valve.
  6. Lubricate the ends of the new angle stop valve and thread them into the new flexible tube.
  7. Connect the opposite end to the faucet.

Straight Top Shut-Off Valve for a Copper Pipe Installation 

  1. Start by loosening and disconnecting the water supply tube. Next, lift out the old adapter and set it aside.
  2. Press the new valve directly into the existing ferrule while coating the inside with a pipe-joint compound.
  3. Pull up the compression nut and thread it into the valve. Tighten the nut until snug,
  4. Reconnect the supply tube to the faucet.

This final step applies to both procedures.

Turn the water back on and check your new valves for leaks. If there are leaks, tighten the valves only until the leaks stop or a quarter turn. Then pat yourself on the back for a job well done.

Common Problems

Here are some common issues you may have with your pipes and valves. 

The Valve Has Become Stuck

If you do not routinely turn your valves, they can become stuck. I always find that a simple fix is to use a lubricant like WD-40 and check for leaks. Then, tighten the valve again and check for ease of movement and leaks.

Leaking Valve

The sound of dripping water will indicate a leak in an existing valve or one you replaced. If the valve is leaking, loosen it, then tighten it a quarter turn past when the leak stops. Be careful! You mustn’t pull the valve too much as it will strip it, and you will have to replace it.

The Valve Partially Closes 

Try WD-40 to tighten it. If it remains stuck, it may be cross-threaded into the pipe. Remove the valve from the line and rethread it. 

Frozen Pipes

In colder climates, the pipes may have frozen and burst, which will cause a water leak at the shut-off valve. So the first step is to shut off the water supply to the house. For frozen pipes, call your friendly neighborhood plumber.

Finding a Qualified Plumber

There are simple steps to follow when hiring a qualified contractor. Of course, as with any licensed professional, due diligence is the first step. Now, you may think getting the quote should be first. It isn’t. Research, research, research! 

There are multiple locations for reviews on the internet. As with anything, take each review with a grain of salt. Read through several reviews to see if there are common themes. 

Be sure your plumber is licensed and insured, but be aware that the person who arrives to do the work may not be the one who holds the license.

When you decide which one to call, ask them what their experience is before you tell them what your problem is. Next, ask what the hourly charges are if there is a separate visit charge, and when they expect payment, then get it in writing. Finally, if satisfied with the discussion, book an appointment.

The advantage of contracting a large company is that your issue will likely get seen to faster, thanks to extra manpower. A disadvantage is if there is a problem, it may be challenging to find a resolution.

An advantage to hiring a licensed independent contractor is they have more experience. The disadvantage is that they are usually booked well in advance, so you may have to wait if your need is urgent.

Tips for a Happy Plumber

  1. Give an accurate description of the problem so the plumber does not waste their time or your money.
  2. Open the cabinets and remove all household items. 
  3. Drain any standing water by opening a faucet at the lowest level in the house.
  4. Be willing to clean up yourself, but have the cleaning supplies for them to use. 
  5. Be organized and ready to go when the contractor arrives.
  6. Finally, write an accurate review of your experience.

Why Should You Have Shut-off Valves?

Let me tell you about what happened to me, so you can learn from my mistakes! The house in question was located in the north and received an average of 200 inches of snow annually. I went on vacation and decided to turn the heat off to save money, inadvertently freezing the plumbing. My son stopped by when I was gone, turned the heating back on over a weekend, then left it on when he left.

Upon my arrival at the house, I noted steam on the windows. The thought entered my head that it was negative three degrees Fahrenheit outside. I heard the water running after advancing through the porch and the house door. I looked down the hall and noted a toilet was dangling through the ceiling.

As I cautiously ascended the stairs and approached the bathroom to shut off the cascading waterfall from the fractured pipes, I found no shut-off valves in the bathroom. Wading to the shut-off valve through two feet of water in the basement is not something I will ever want to repeat.

The moral of the story is? You only need shut-off valves when you need them!

The Importance of a Shut-off Valve Under the Bathroom Sink

Now you know the issues no shut-off valve under the bathroom sink can cause. Double-check that you have a proper one!

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