Bosch 520PN Applications Manual page 30

2 8 | THERM/GREENTHERM Tankless Water Heaters
11.1.2 Solar DHW system with gas tankless water heater
booster and recirculation loop
Similar to 10.2.1 with domestic hot water recirculation
added. The tankless water heater only runs when solar
heated water needs a boost. See applicable models listed
below.
f
Thermostatic valve 1 ensures that warm solar water
bypasses the water heater and directs cooler water
through the appliance when reheating is needed.
f
Thermostatic valve 2 acts as a tempering valve that
brings potentially hot water temperatures down to a
level that is safe for the inhabitants
Applicable models: Bosch 830 ES, 940 ES, 940 ESO,
C 950 ES, C 1050 ES, C 1210 ES.
Data subject to change
System parameters:
f
Honeywell AM101 Thermostatic Valves required for
proper operation;
f
Remove check valves from Thermostatic Valve 1 as it is
used as a diverter valve;
f
Thermostatic Valve 2 is a tempering valve;
f
Recommended setpoint 120°F for both Valves;
f
Set tankless water heater temperature to 140° F
See Chapter 5.2 for recirculation pump parameters
Applications Manual
Bosch Thermotechnology Corp.