Vaillant ecoTEC plus VU 6/5-5 Series Installation And Maintenance Instructions Manual page 65

5 Outdoor temperature sensor, flow temperature
sensor (optional, external), DCF receiver
6 Circulation pump remote control
7 Power coding resistor
8 Return temperature sensor
9 Flow temperature sensor
10 Fan
11 Surface-mounted thermostat/burner off
12 24 V DC room thermostat
13 Bus connection (digital room thermostat/control)
0020244997_07 Installation and maintenance instructions
14 Prioritising diverter valve
15 Water pressure sensor
16 Cylinder temperature sensor
17 Cylinder contact "C1/C2"
18 Gas group coding resistor
19 Additional relay (select via D.026)
20 Internal pump
21 Ignition electrode
* Depending on product type
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