Basic Tank Loading With Domestic Recirculation - Bosch GWH 715 ES Applications Manual

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11.2 Basic tank loading with domestic recirculation

The following application outlines general tank loading with one or
more gas tankless water heaters in parallel. Domestic hot water
recirculation shown is optional.
System parameters:
• Aquastat/tank sensor Tset 120-140°F, <10°F differential.
• 30-119 gallon storage tank recommended
• DHW return line can tie directly into tank if fi ttings are available.
• Individual pumps (i.e. UP26-99) can be used on supply to each
heater or one pump (as shown) for the entire system
See Chapter 5.1 and 5.2 for pump parameters
Domestic
Hot Water
supply
Aquastat
or tank sensor
Hot water
DHW
recirculation
recirculation
return line
pump
Service
Well
valve
thermometer
Bosch applications manual | 06.2009
Bosch GWH 715 ES, Bosch GWH C 800 ES, Bosch GWH C 920 ES/ESC
Symbols
Pressure
Solar
Drain
relief storage
valve
valve
tank
Aquastat / Water Heater setpoints
Model Number Aquastat setpoint
GWH C 920 ESC ≤140°F
GWH C 920 ES ≤126°F*
GWH 715 ES ≤126°F*
GWH C 800 ES ≤126°F*
* If local codes require higher setpoint or to increase the recovery
capacity of the water heater, contact Bosch Thermotechnology.
Bronze or
Flow
stainless
direction
steel
circulator
BOSCH THERMOTECHNOLOGY CORPORATION
Bosch applications manual
Water heater
setpoint
14°F above
Aquastat setpoint
140°F
140°F
140°F
Cold
Water
Supply
Flow
Potable
check
water
valve
expansion
tank