Application's Manual

Data subject to change without notice | 01.2011 BOSCH THERMOTECHNOLOGY CORPORATION
THERM Tankless Water Heater Applications Manual | 7
5 Pump sizing
The following section outlines sizing pumps for domestic hot water
circulation and tank loading. Only models approved for such
applications are listed in this section.
 Pump must be bronze or stainless steel.
 Size the pump according to the system pressure drop chart
below.
 Maximum flow allowed through the recirc loop is 5 GPM.
If the water heater is used within an approved hot water
recirculation application and supplied with circulated
water, the heat exchanger warranty is decreased. Please
refer to the installation manual for detailed warranty
period information.
Run the system for 30 minutes to remove debris from the
plumbing. Then remove the unit‘s inlet water fi lter to
decrease pressure drop through the system.
If the inlet water fi lter, when removed, contains debris
install a Y-strainer (installer supplied) on the cold water
inlet.
5.1 Pressure drop curves
0
10
20
30
40
50
60
70
0.50.40.30.20.10.0
Flow
(
GPM
)
Pressure (Feet of Head)
C 800 ES,
C 1050 ES
C 920 series,
C 1210 series
2400 ES,
2700 ES,
GWH 715 ES,
830 ES,
940ES/ESO
660 EF/EFO