Managing Thermal Expansion Alerts from Your Automatic Water Shutoff Valve

Thermal expansion is incredibly common, as well as solvable - oftentimes, with an expansion tank! This guide is intended to help you manage Thermal Expansion or Pressure-, Leak-related alerts from your automatic water shutoff valve (i.e., homeowners with Flo by Moen, Phyn, Streamlabs devices). We help clients every day with questions like this through Watchdog; you can learn more on our website and activate now for 1-on-1 support.

Continue reading for general support with these alerts!

Why Am I Receiving An Alert?

Automatic water shutoff devices are installed on the main water line and typically monitor the line’s water flow and temperature, 24/7. When unusual flow is detected (i.e., burst pipe), these devices automatically shut off the water to prevent significant water damage and loss. A closed valve usually creates a closed system and high pressure as a result of thermal expansion can lead to leaks, burst pipes, and damage to appliances including water heaters and fixtures​. While turning off the water in response to a severe water-loss event gives peace of mind, thermal expansion results in high pressure that can have significant adverse effects on the entire plumbing system (including leaks). 

You may be experiencing thermal expansion alerts or pressure-related alerts from your automatic water shutoff valve. Some automatic water shutoff valves not only monitor the water flow and temperature, but also water pressure. High pressure is typically alerted to when the PSI rises above 80 (PSI), while low pressure is often alerted to when the PSI drops below 40 PSI.

In addition to monitoring the pressure in real-time as you use water, these devices also perform a nightly test* that involves closing the valve and monitoring the pressure (PSI) in real-time to check for fluctuations (if there is no leak, the PSI will not change). By checking for "pressure loss", these devices are able to identify the smallest possible leak on the supply line (i.e., from pinhole leak, dripping faucet, running toilet) – and, one that may be too small to result in an automatic water shutoff. This is a proactive method to notify you of small leaks, and the resulting small drip/leak alert can be referring to anywhere on the supply line (our team is full of experts with experience and knowledge to help identify the source of the pressure loss, to help clear the alert).

Thermal expansion may come into play when the device is running this nightly pressure loss test. When the valve closes, if the device sees the pressure rate (PSI) go UP (other options are for the PSI to stay the same (suggests no leak), or go DOWN (suggests a small leak), thermal expansion is present! In such cases, the device may show a failed test or a specific “Thermal Expansion” alert. You can test this yourself by closing the valve and monitoring the resulting PSI in the app, if it goes up. In the process of thermal expansion, water is expanding due to heat and this can be problematic in a closed system.

*NOTE: If the device attempts to run the test, and detects water to be running (i.e., you are washing your hands at this moment), the device will immediately stop the test and turn back on the water; you may not even notice. After, the device will attempt to re-run the test at a later time, or simply run again during the next 24-hour period.

What Next? 

Automatic water shutoff valves are designed to turn off the water automatically and may stay closed for a sustained amount of time to prevent costly water damage. When the valve is closed, thermal expansion may occur if there is no expansion tank or another reason for the increase in pressure detected. This often indicates the need for an expansion tank on your water heater (tank or tankless). 

Expansion tanks provide space for the expanding water, relieving pressure from the system. Installing one not only ensures the optimal performance of your shutoff valve but also protects your entire plumbing network from the dangerous and lasting effects described above. Our team of plumbing experts can help install an expansion tank, or find a solution to help keep the pressure in your plumbing system at a safe level. You can schedule service online or call us at (844) 823-2453. With Watchdog, you get enhanced alert support from our team (remote support, with access to your alerts) and save 10% plus more on any service visit. Learn more here or contact our team at solutions@beagleservices.com.

While an expansion tank may be a simple solution for many plumbing systems, you find more tips and information on how to address thermal expansion alerts here in this related blog article: Understanding Thermal Expansion.