Controlling the water temperature

What should I know about hot water?

Hot water is something we all take for granted. But maintaining the proper water temperature is more complicated than you might think. Water that is too hot, of course, causes skin damage.

Most people know about the dangers of scalding.

But water that is too low can allow the growth of bacteria. Most bacteria is harmless, some is beneficial. But Legionnaires disease is deadly. The Centers for Disease Control and Prevention (CDC) has a great article about it. Click Legionella

So, there isn’t anything I can do, right?

Ha, ha. Of COURSE there’s something you can do! For a once-and-done solution, consider installing a valve at your water heater that mixes cold water with the hot to get just the right temperature you need. You can keep the heater set to temperatures that can kill the bugs and still not scald your hands.

It sounds complicated, but it’s not. A transfer tube runs from the inlet side of the water heater and runs to a mixing valve. That valve has a dial on it. Turn the knob one way or the other, and more or less cold water mixes with the hot.

Set the water heater to 140 degrees, and adjust the dial to produce 120 – 125 degrees at the faucet.


I got these photos from, but also read an article from some other inspectors. Want to learn more?

Click Other inspector’s blogs