Journeyman Plumber ExamWater Supply SystemsMedium
A plumber is designing a hot water recirculation system for a large custom home to ensure instant hot water at all fixtures. To maintain system efficiency and prevent short-cycling of the water heater, what type of valve is essential to install on the recirculation return line just before it reconnects to the water heater inlet?
- AA check valve.
- BA ball valve.
- CA gate valve.
- DA pressure relief valve.
Show answer & explanationAnswer & explanation
Correct answer: A. A check valve.
A check valve is essential in a hot water recirculation return line. Its purpose is to prevent the cooler water from the return line from flowing backward into the main hot water distribution system when the recirculation pump is off or when system pressure changes, which would defeat the purpose of the recirculation system and lead to cold water at hot water taps.
Why the other options are wrong
- B. A ball valve is for full on/off flow and does not prevent backflow automatically.
- C. A gate valve is for full on/off flow and does not prevent backflow automatically.
- D. A pressure relief valve protects against overpressure, not reverse flow.
Recirculation System Check Valve
A one-way valve installed in a hot water recirculation return line to prevent the backward flow of cooler water into the main hot water supply, ensuring efficient operation.
- Ensures water flows only towards the water heater.
- Prevents mixing of hot and cold water in the main hot water line.
- Crucial for maintaining hot water availability and system efficiency.
Memory trick: Recirculation's flow: one way to go, check the valve to know.