Space Heating Applications - Bosch 940 ESO Instruction Manual

7.5

Space heating applications

Warning: If the set point temperature is
above 120 F means should be undertak-
en to protect users of potable water
from scalding.
Warning: Propylene glycol may be
used for freeze prevention ONLY on the
space heating side of the heat exchang-
er. Do not use ethylene glycol (automo-
tive antifreeze).
Warning: The use of a flow switch may
be used to ensure DHW priority and to
prevent "cold-blow" situations when the
Bosch tankless water heater is used
with an air-handling system. The flow
switch should be used to disable the
blower on the air-handling system when
domestic water is used.
70
60
50
40
30
20
10
0
0.0
Fig. 31 Pressure drop curve
6 720 644 956
1.0 2.0
Warning: ensure the primary pump is
sized to provide adequate flow for the
system heat load.
For Pump sizing please refer to the
i
pressure drop curves, Fig. 31. Also
remember to account for system piping
pressure
primary pump size for adequate flow
through the water heater (minimum of 1.7
GPM).
Bosch tankless water heaters are allowed to be used in
combination DHW and space heating applications
(open-loop setup). It is not allowed to use Bosch
tankless water heater in a space heating only
application (closed-loop setup). Bosch supports
combination DHW and space heating in an open loop
configuration if plumbed similar to Fig. 32. Use of a
Bosch tankless water heater in a combination DHW
and space heating application will result in the product
warranty being reduced to 3 years.
940ESO
3.0
Flow (GPM)
Installation instructions
loss. Recommendation
4.0 5.0
6720644956-15.1V
for
23