How to Install a Toilet Mixing Valve

thermostatic mixing valve with multiple plumbing attachments
  • 1-3 hours
  • Intermediate
  • 25-50
What You'll Need
Mixer valve
Copper pipe
Compression fittings or solder
Wrench
Teflon tape
Wire wool
Stop valve
What You'll Need
Mixer valve
Copper pipe
Compression fittings or solder
Wrench
Teflon tape
Wire wool
Stop valve

A mixing valve is often installed in your home's water system if you are experiencing problems with condensation or sweating of the water tank. This is a fairly common problem and fitting a toilet mixing valve can be enough to resolve the issue. A toilet mixer valve works by mixing the cold and hot water to prevent the water tank from sweating which can be frustrating for many people.

Step 1 - Attaching the Pipe

Decide now whether you will be using compression fittings or soldered joints. Compression fittings are easier but more expensive, which is why most professionals will use soldered joints. However, compression fittings are ideal for DIY projects.

Connect the mixer valve onto a small piece of copper pipe which is around 6 inches long. This can then be connected to the supply lines when you're ready. The pipe can then be connected to the water supply using the compression fittings.

Step 2 - Switching the Water Off

You must switch off the water before attempting any work on your plumbing system. You should also drain the system of all water so that it is safe to cut into the pipes.

Step 3 - Connecting to the Water Lines

If you insert this into existing water pipes, you will need first to cut the pipes. Then clean the pipes using a piece of wire wool.

Wrap Teflon tape around the ends of the pies and fix the mixer valve onto them by using the compression joints. Make sure that the valve is positioned correctly before tightening the joints using a wrench.

The valve needs to be connected to both the hot and cold water lines. While fitting a new mixer valve, you might as well fit a stop valve so that you can shut the water off to your toilet easily if ever required.

Step 4 - Finishing the Job

Now all you need to do is use the compression fittings to connect to the water lines connected to the toilet. You can now turn the water back on very slowly, start turning the cold line on, and then turn the hot on. Check that there are no leaks as you are doing this.

Once you're sure there are no leaks, you can put the floorboards down and cover the pipes up again. Leaks can be very damaging if they are not detected quickly.

Step 5 - Testing

Now, all you need to do is flush the toilet to test the system and get rid of any air inside the pipes. Hopefully, this will cure any problems that you have been having with sweating.

This is one of the easiest and most successful methods of dealing with condensation on your toilet's water tank. However, if this doesn't cure the problem, you might need to call in a professional.