CSLB C-36 Plumbing ContractorFixture and Appliance InstallationMedium
A plumber is installing a commercial dishwasher in a restaurant kitchen. The local health department requires that the final rinse water reaches a minimum temperature of 180°F (82°C) to ensure proper sanitization. The building's hot water supply is consistently at 140°F (60°C). What additional component is required to meet the health department's sanitization standard?
- AA pressure reducing valve.
- BA tempering valve.
- CA booster heater.
- DA thermal expansion tank.
Show answer & explanationAnswer & explanation
Correct answer: C. A booster heater.
A booster heater is specifically designed to raise the temperature of the incoming hot water to the higher temperatures required for sanitization in commercial dishwashers, typically 180°F (82°C).
Why the other options are wrong
- A. A pressure reducing valve lowers water pressure and has no effect on water temperature.
- B. A tempering valve (or mixing valve) blends hot and cold water to achieve a specific, lower temperature, which is the opposite of what is needed here.
- D. A thermal expansion tank absorbs excess pressure from thermal expansion and does not increase water temperature.
Dishwasher Booster Heater
An auxiliary electric or gas heater used with commercial dishwashers to raise the incoming hot water temperature to the high levels required for sanitization.
- Typically heats water to 180°F (82°C) for final rinse.
- Essential for meeting health code sanitization standards.
- Installed in-line with the dishwasher's hot water supply.
Memory trick: To sanitize the stack, a booster heater puts the heat on track.