Instructions / Assembly
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WHL-590 REV. 7.27.16
Figure 24 – Piping with Recirculation – NOTE: There is a Built-In Flow Check in the Internal Recirculation Pump Loop
NOTE: For installations where internal pump is not adequate for the recirculation loop, an additional pump can be installed and
powered by the water heater (2A Max). See Pressure Drop and Pump Curves, this manual.
NOTES:
1. Minimum pipe size should match connection size. Upsize pipe accordingly if greater flow is required.
2. A thermal expansion tank suitable for potable water must be sized and installed within this piping system between the backflow
preventer and the cold water inlet.
3. All circulators should have an integral flow check.
4. Drains and check valve between water heater and piping will assist in purging air from system.
5. These drawings are meant to demonstrate system piping only. The installer is responsible for all equipment and detailing required by
local codes. In Massachusetts, you must install a vacuum relief valve per 248 CMR.
6. Mixing valve application is optional, but recommended to help prevent scalding.
7. Always shut off power to the water heater or isolate the heater from the system if ANY plumbing work is to be done. Running the
water heater without water will result in dry-firing.
NOTE: These drawings are meant to show system piping concept only. Installer is responsible for all equipment and detailing required
by local codes.