Installation / Operation Instruction Manual

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Installation instructions
RTG-K-199/160N/X2 – 6 720 813 642 (2022/06)
• Insulate pipes to prevent heat loss
Fig. 19 Cascading installation example
It is not possible to have both cascading and recirculation active
at the same time.
It is not possible to cascade a RTGK with a RTGL.
4.16 Space heating applications
WARNING:
▶ If the set point temperature is above 120°F (49 °C),
precautions should be taken to protect users of potable
water from scalding.
NOTICE:
▶ The use of a flow switch is recommended to ensure DHW
priority and to prevent “cold-blow” situations when the
Bosch tankless water heater is used with an air handler.
Air handler installation must include a pump.
The flow switch should be used to disable the blower on the
air-handling system when domestic water is used.
NOTICE:
▶ Ensure the primary pump is properly sized to provide
adequate flow for the system heat load.
For external pump sizing please refer to the pressure drop
curves, fig. 21. Also remember to account for system piping
pressure loss. A minimum of 1.7 GPM is recommended to
provide adequate flow through the water heater when
determining the size of the primary pump.
RTG-K-199/160N/X2 tankless water heaters are approved
for use in combination DHW and space heating applications
(open loop setup).
These water heaters are not approved for use in space heating
only applications (closed-loop setup). Bradford White
supports applications of combination DHW and space heating
in an open loop configuration if plumbed similar to fig. 20.
Please see warranty document for additional details.