In older homes with less-than-adequate plumbing, there’s only so much hot and cold water to go around. That’s why your shower rains hellfire when someone flushes the toilet. The toilet refills the tank with cold water, drawing cold water away from your shower. What remains is scalding hot water. Ouch!

The opposite can happen, too. When someone in your home turns on the dishwasher, the appliance demands its share of hot water, which means less hot water for you. Burr!

Fortunately, you have a couple of inexpensive solutions: a pressure-balance shower valve or a thermostatic valve. Both prevent sudden temperature changes. That means no more unpleasant surprises.

Pressure-Balance Shower Valve

This type of valve has one handle that controls both the volume and the temperature of the water within the shower. There is also a maximum point that stops the valve from going further. Typically, a sliding disc is used to control the water pressure. This feature allows the pressure of colder water to be distributed else-where and prevents cold bursts of water during your shower. The temperature should not fluctuate more than a few degrees.

Thermostatic Shower Valve

This valve has two separate handles for water volume and temperature. Thermostatic valves are built to react to the temperature of the water rather than the pressure of the water. There is a heat reacting element to the valve that expands or contracts depending on the water temperature. Water flow is then tightened is water becomes too cold to ensure that only hot water exits the shower.

Bottom line: Both of these valves are appropriate options for your shower. It is completely up to you to choose which valve better suits your needs. Typically, a pressure-balance valve is less expensive than a thermostatic valve. With that said, if you live in an area with extreme water fluctuations, then a thermostatic valve may be worth the investment. No matter which option you choose, professional installation is strongly recommended. To schedule an appointment with Evergreen Plumbing & Mechanical, call (503) 714-7004.