1-Boiler System With Unimat Ut-L Boiler: Boiler And Heating Circuit Control Unit - Bosch UT-L 1 Technical Manual

9.4

1-boiler system with UNIMAT UT-L boiler: boiler and heating circuit control unit

Fig. 38 System example for UNIMAT UT-L boiler CFB control unit for boiler and heating circuit control unit (list of

abbreviations
The circuit diagram is only a schematic
illustration! Information regarding all
system examples  page 47 ff.
AREA OF APPLICATION
• UNIMAT UT-L boiler
• boiler and heating circuit control unit
Brief description of the system
• Control of the minimum return temperature by
overriding the heating circuit actuators
• 2-stage or modulating burner mode
• Simple layout
UNIMAT
PK KR
FZ
FK
VK RK
CFB 930
+ CMM 920
page 47)
HK
THV
FV
PH
SH
6 720 803 977-18.1itl
Function description
The heating circuits are controlled via the mixer
modules. The boiler circuit pump provides hot flow
water to the return. This increases the boiler return
temperature. To raise the return temperature, the
heating circuit actuators are regulated with overriding
control. The flow rate to the boiler is restricted until the
set value for return temperature control has been
reached by mixing in flow water. Once the set value for
the return temperature has been reached, heating
circuit control is re-enabled.
Special design information
• If a check valve is installed, the boiler circuit pump
run-on time should be five minutes. If no check valve
is installed, set a run-on time of 60 minutes.
• In conjunction with the CFB control unit, the
maximum possible flow temperature of a heating
circuit with mixer is 90 °C.
System examples | 57
VV
VR
6 720 807 794 (2013/04)