Westinghouse Premium WGRT 199 Series Installation, Start-Up, Maintenance, Parts, Warranty page 22

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Figure 14 - Cascaded Water Heaters with Storage Tank
Figure 15 - Cascaded Water Heaters with Storage Tank and Recirculation
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.
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8. When using unit with storage tank, the setpoint of the water heater needs to be at least 20 F higher than the setpoint of the Aquastat on
the tank. Pump selection must meet a minimum flow rate requirement of 2 GPM.
NOTE: These drawings are meant to show system piping concept only. Installer is responsible for all equipment and detailing required by
local codes.
whl-004 Rev. 000 Rel. 013 Date 5.1.18