Bosch C 1210 ES Applications Manual page 26

2 6 |
10.2.2 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. Buffer tank provides small amounts of DHW instantly and
increases comfort by smoothing out DHW temperature. See
applicable models listed in the fi gure below.
Thermostatic valve 1 ensures that warm solar water bypasses the

water heater and directs cooler water through the appliance
when reheating is needed.
Thermostatic valve 2 acts as a tempering valve that brings

potentially hot water temperatures down to a level that is safe for
the users.
Applicable Bosch Models:
•Bosch 830 ES
•Bosch 940 ES/ESO
•Bosch C 1050 ES
•Bosch C 1210 ES/ESC
Ariston GL8ti
mini tank
Honeywell Well
Am-1 series thermometer
thermostatic
mixing
valve
Data subject to change without notice | 01.2011
Hot Cold
Thermostatic
valve 1
Thermostatic
Domestic
valve 2
hot water
Water
supply
Symbols
Pressure
Service
relief
valve
valve
THERM Tankless Water Heater Applications Manual
System parameters:
Honeywell AM101 Thermostatic Valves required for proper

operation;
Remove check valves from Thermostatic Valve 1 as it is used as a

diverter valve;
Thermostatic Valve 2 is a tempering valve;

Recommended setpoint 120°F for both Valves;

Set tankless water heater temperature to 140° F

Ariston mini tank will provide increased temperature stability and

quicker hot water delivery. (recommended but not required)
Choose size of the Ariston mini tank to match the volume of the

recirculation loop
See Chapter 5 for recirculation pump parameters
Solar
Controller
Tank
sensor
Solar
Potable Flow
storage
water direction
tank
expansion
tank
Collector
sensor
Solar
Pump
Station
Flow
Circulator
check
valve
BOSCH THERMOTECHNOLOGY CORPORATION
Drain
valve