How to Install a Hot Water Mixing Valve : Tips and Tricks

This article will show you how to install a hot water mixing valve onto your own water lines with the help of some simple tools. A hot water mixing valve mixes a little hot water to the cold water line going to your toilet to keep your toilet from sweating or forming condensation around the toilets tank.

Preparing the area for valve installation

Draining the System

Turn off the water where it enters the house. Then, drain the system by turning on a faucet in the highest point of the house as well as the lowest point of the house such as an outdoor faucet.

Label the Lines

To protect the water heater, temporarily turn it off at the breaker. Label the hot and cold lines with colored electrical tape.

Installing a stop and waste valve

Cut the Pipe

The first step is to cut off a section of the cold water line to insert the mixing valve. Cut out a small section of both the cold and the hot water lines using a pipe cutter.

Install the T Fitting

Install the T fitting on the hot water pipe. Use the torch and flux to solder it onto the existing hot water line.

Attach the stop and waste valves

Use the same soldering technique to attach the stop and waste valves onto the hot and cold supply lines. Now you can turn on the main water supply again.

Installing the mixing valve

Attaching the pipe and fitting assembly

Solder the adapter onto a short piece of copper pipe, six inches or so. This will give you something you can attach both to the supply lines and to the anti-sweat valve. Attach the pipe and fitting assembly to the valve by using the compression fitting that comes with the valve.

Connecting the valve to the water lines

Add a little teflon tape onto the ends, insert the pipe and slip the compression fitting nut over the pipe. Back it up to the appropriate location over the joint and tighten with a wrench. Next, connect the valve assembly to the water lines by soldering the connections on both the hot and cold water lines at the stop and waste valves.

Connecting the T assembly to the mixing valve

Connect the 'T' assembly from the hot water line to the mixing valve. Use a compression fitting or solder, which ever you prefer. To make the final connections, secure a pipe onto the remaining port on the mixing valve with a compression fitting. Then, install vent couplings on the other end.

Finishing the Project.

Solder the final joints. Slowly turn on the water at the new stop and waste valves. Start with the cold line, then the hot. Finally, flush the toilet a few times to get the air out of the lines.