TL;DR
A tempering valve is a thermostatic mixing valve that blends hot water from the tank with cold supply so fixtures receive water at a set safe temperature, commonly 120 degrees Fahrenheit. It lets a water heater store at 140 degrees, which suppresses Legionella growth, without delivering scald-level water to taps.
What it means
A tempering valve is a thermostatic mixing valve that blends hot water from the tank with cold supply so fixtures receive water at a set safe temperature, commonly 120 degrees Fahrenheit. It lets a water heater store at 140 degrees, which suppresses Legionella growth, without delivering scald-level water to taps. Whole-house models are listed to ASSE 1017 and install at the heater outlet, with an adjustment cap that sets the blend point.
Where it sits in the glossary
Tempering valve is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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