What is a tempering valve?

Terry Smith • December 17, 2025

What is a tempering valve?  www.americanplumbingla.com 

What is a tempering valve? 
www.americanplumbingla.com 
#americanplumbing 
#geriatricgymrat 
#temperingvalve
#federalgovernment 
#plumbingrepairs

A tempering valve is a plumbing safety device that mixes hot water with cold water to deliver water at a controlled, safe temperature.

What it does

Reduces very hot water from a heater to a preset temperature

Prevents scalding at taps, showers, or fixtures

Keeps water temperature consistent even if pressure or supply changes

Where it’s commonly used

Domestic hot water systems (homes, apartments)

Bathrooms, showers, sinks

Solar and heat-pump water heaters (which often store water at higher temperatures)

Hospitals, schools, childcare centers (where safety standards are strict)

Why it’s important

Water heaters are often set to 60°C (140°F) or higher to prevent bacteria like Legionella

Tempering valves typically reduce outlet temperature to around 45–50°C (113–122°F), which is much safer for skin

How it works (simple)

Hot water enters the valve

Cold water enters the valve

The valve blends them to a set temperature

Mixed water exits to fixtures

Tempering valve vs thermostatic mixing valve (TMV)

Tempering valve: Usually serves an entire house or group of fixtures

TMV: More precise, often used at individual outlets (like a single shower)
By Terry Smith February 24, 2026
How to adjust a Toto toilet tank fill valve. www.americanplumbingla.com #americanplumbing #GeriatricGymRat #Toto #ToiletFillValve  #ToiletRepairs 
By Terry Smith February 23, 2026
No more pipe threading oily mess! www.americanplumbingla.com #americanplumbing #geriatricgymrat #MegaPress #OilyMess #GasPipe
By Terry Smith February 23, 2026
Insulation blanket can ruin a water heater! www.americanplumbingla.com #AmericanPlumbing #geriatricgymrat #InsulationBlanket #WaterHeater #Humidity
By Terry Smith February 20, 2026
Smoke bomb size matters! www.americanplumbingla.com #americanplumbing #geriatricgymrat #SmokeBombs #SmokeTest #PlumbingRepairs
By Terry Smith February 19, 2026
You should be able to trust your plumber! www.americanplumbingla.com #AmericanPlumbing #GeriatricGymRat #WaterHeater #ControlValve #TrustYourPlumber 
By Terry Smith February 17, 2026
Smoke test in progress! www.americanplumbingla.com #AmericanPlumbing #GeriatricGymRat #SmokeTest #SewerOdor #RatDroppings
By Terry Smith February 12, 2026
Do not waste your time! www.americanplumbingla.com #AmericanPlumbing #GeriatricGymRat #BrassCleanoutPlug #CastIronPipe #Stoppage
By Terry Smith February 11, 2026
Gas piping must be wrapped! www.americanplumbingla.com #AmericanPlumbing #GeriatricGymRat #GasPiping #GasLeak #GasRisers 
By Terry Smith February 10, 2026
Gas leak? www.americanplumbingla.com #americanplumbing #geriatricgymrat #GasLeak #GasLineRepair #PlumbingRepairs
By Terry Smith February 9, 2026
A victim of the freeze! www.americanplumbingla.com #AmericanPlumbing #GeriatricGymRat #Freeze #Flowmeter #BackflowDevice