4.3 ZWC/ZSC 21/24/28/35 - 3 MFA / MFAE / MFAP types
Fig. 15
4.1 Ignition transformer
6 Temperature limiter for heat exchanger
6.3 Temperature sensor, DHW (ZWC)
18 Central heating pump
32 Flame sensing electrode
33 Igniter electrodes
36 Temperature sensor in CH flow
52 Solenoid valve 1
52.1 Solenoid valve 2
56 Gas valve
68 Control solenoid
84 Motor 3-way diverter valve
135 On-/Off-switch
136 Temperature control for CH flow
151 Fuse T 2,5 A, AC 230 V
153 Transformer
161 Link
226 Fan
228 Differential pressure switch
300 Code plug
302 Earth connection
303 HW cylinder NTC sens or connection (ZSC)
310 Temperature control for hot water
312 Fuse T 1,6 A
313 Fuse T 0,5 A
315 Terminal block for programmer (EMS bus) and outside tem-
perature sensor
319 Terminal block for cylinder thermostat or external limiter
328 Terminal block for AC 230 V Mains supply
328.1 Link
413 Flow meter (turbine) (ZWC)
428 Connection for circulation pump (ZSC others)
432 HW cylinder DHW sensor (ZSC, optional)
463 Diagnostics interface
6 720 613 084-05.1O
230 V
9V/25 V
230V/AC
135
153
312
313
ST19
300
315
303
319
161
ST15
ST8
ST9
ST17
56
32
6
4.1
ST5
ST4
33
68
52
52.1
413
228
36
226
M
18
M
ST10
L
NLsLR
328.1
328
302
151
+
–
A
F
136
310
463
432
ZSC
84
M
ST25
428
ST19
315
ST15
6.3
+
–
A
F
ZWC
ST17
84
M
ST19
315
ST15
+
–
A
F
ZC
ST17
22 | Electrial Wiring Diagrams
6 720 660 238 (2008/07)
22