Recirculation Pump Sizing - heat-timer ETS Installation And Operation Manual

Recirculation Pump Sizing
For proper operation of the ETS, the assembly must be installed in a system with constant recirculation. The ETS
provides a dedicated recirculation connection.
For optimum valve function, it is recommended that the building recirculation temperature is at least 7°F lower
than the desired setpoint temperature. In addition, it is recommended that the HOT water supplied to the ETV
valve is at least 20°F above the desired setpoint.
The recirculation pump (not provided) must be properly sized for the following recirculation rates:
In systems without a building recirculation line, it is recommended that a flow switch (not provided) is installed.
HEALTH RISK! Any domestic hot water system that does not utilize a constant building
recirculation line poses a potential risk of stagnant water in the system. Stagnant water
provides ideal conditions for the growth of bacteria, such as Legionella.
The flow switch should be located on the MIXED outlet field piping above the ETS assembly. Activation of the
flow switch should be at the lowest potential draw of the system.
Refer to "Wiring the Flow Prove" on page 42 for wiring to the ETV Platinum Plus module for a flow switch
(Prove).
Refer to "Flow Switch" on page 28 for proper STARTUP menu settings for installations using a flow switch.
Heat‐Timer Corp.
Table 3: ETS Recommended Recirculation Flow Rates
Model
ETS‐15
ETS‐20
ETS‐25
ETS‐30
ETS‐40
Recirculation
Flow Rate
10 gpm
15 gpm
15 gpm
30 gpm
30 gpm
WARNING
Installation Instructions 15
059326‐00 Rev D