Service Thermostatic Mixing Valve for Scald Prevention
Why it matters
A failed mixing valve allows excessively hot water (140°F+) causing severe scald burns, especially to children and elderly. A properly set valve prevents burns while maintaining adequate hot water.
Stop forgetting to do this.
Hearth generates a personalized maintenance schedule so you never miss another service thermostatic mixing valve for scald prevention.
How to do it
- 1
Locate the thermostatic mixing valve (usually under the sink or behind the shower valve) or identify if your water heater has a built-in mixing valve.
- 2
Use a thermometer to test hot-water temperature at the faucet or shower; ideal is 110–120°F (43–49°C) for household safety.
- 3
If temperature exceeds 120°F, turn off the water and look for an adjustment screw or cartridge on the mixing valve.
- 4
Consult the valve manufacturer's manual for adjustment procedure; typically turning the screw clockwise reduces temperature.
- 5
Make small adjustments (1/4 turn) and retest; repeat until safe temperature is reached.
- 6
If the valve won't adjust or leaks, call a plumber to replace the internal cartridge or valve assembly.