When planning to install a Rheem hybrid heat pump water heater (HPWH) with a mixing valve, a question arises: should I opt for flexible stainless steel connectors or hard copper piping? Additionally, what is the best strategy for positioning check valves and the expansion tank to prevent any interaction issues? It’s crucial to ensure that these components work harmoniously together to optimize efficiency and maintain consistent water temperatures. What are your thoughts on the best practices for this setup?
2 Likes
Hook up your heat pump like this: Run the hot water line from the heater straight to the mixing valve’s hot side. Then, link the valve’s cold side to your cold water supply. The mixed water comes out of the valve and goes to your home’s hot water pipes. Put a check valve on the cold feed to stop hot water from flowing backward. Use short, bendable pipes or copper stubs to make repairs easier. Wrap the hot water line between the heater and valve with insulation to keep the water temperature even.
Flexible stainless steel connectors make installation and future servicing easier, while hard copper is more permanent and tamper-resistant. Place the expansion tank on the cold side before the water heater inlet and position check valves so they don’t trap pressure between the heater and tank usually one after the meter/backflow preventer and, if needed, another on the hot side after the mixing valve. This keeps thermal expansion under control and prevents mixing valve backflow.
Hard copper provides strength and a neat finish, while flexible stainless steel makes installation and servicing easier—both are fine if properly sized. Install the expansion tank on the cold line before the check valve, and set check valves to allow thermal expansion without creating pressure traps, ensuring efficient HPWH performance.
When installing a Rheem hybrid heat pump water heater with a thermostatic mixing valve, consider the following best practices:
-
Piping Options
-Flexible Stainless Steel Connectors: Suitable for connecting the heat pump water heater to the plumbing system, offering flexibility and resistance to corrosion. Ideal for reducing vibrations from the heat pump water heater.
-Hard Copper Piping: A durable option that can withstand high water pressure and temperatures. Ensure proper soldering and insulation to prevent leaks and heat loss. Use dielectric unions when connecting copper piping to the water heater’s inlet and outlet. -
Component Positioning
-Check Valves: Install check valves on both the cold water inlet and hot water outlet piping to prevent backflow and ensure proper system operation. Position them near the water heater.
-Expansion Tank: Install an expansion tank to absorb excess pressure caused by thermal expansion. Size it according to the water heater’s capacity and pressurize it to match the incoming water pressure.
Flexible stainless steel connectors make installation easier and absorb vibration, while hard copper offers a cleaner, more permanent look both are acceptable if rated for potable hot water.
Place check valves so they isolate the heater without trapping expansion, and position the expansion tank on the cold side, before the check, to handle thermal growth.
Keep the mixing valve close to the heater outlet, with unions for service, and ensure all components are accessible, supported, and insulated to maintain efficiency and stable temperatures.