lp-441 Rev. 004 Rel. 000 Date 7.2.21
16
H. Applications
Figure 4 - Piping with Recirculation Line and Thermostatic Mixing Valve Piping
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 unit and storage tank 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.
The piping will not support the weight of the water heater circulator pump. Refer to the pump manufacturer’s installation instructions
to properly support the circulator pump. Failure to comply with these instructions could result in substantial property damage, severe
personal injury, or death.
An ASSE 1017 thermostatic mixing valve MUST be installed when using outdoor reset. Failure to do so could result in substantial property
damage, serious injury, or death.
