Bosch GWH C 920 ES - 5 Pump Sizing; Pressure Drop Curves

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Bosch applications manual
Bosch applications manual | 06.2009
BOSCH THERMOTECHNOLOGY CORPORATION
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)
GWH C 800 ES GWH C 920 series
GWH 715 ES