Viessmann MatriX Service Instructions For Contractors page 38

Connection diagrams
Burner control unit connection diagram
Fig. 28
Burner control unit VUC 310
A
Flame monitoring with ionisation current
B
C Vitotronic control unit
3/2-way solenoid valve
D
Ignition unit
E
Fuel valve BV1
F
Suppressor choke box (for 115 and 142 kW)
U
38
(cont.)
F1 Backup fuse
F2 Backup fuse
F6 High limit safety cut-out
F7 Temperature controller
H1 Hours run meter, modulation
H2 Fault message
S1 ON/OFF switch