Vaillant ecoTEC plus Installation And Maintenance Instructions Manual page 62

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)
62
14 Prioritising diverter valve
15 Water pressure sensor
16 Impeller sensor
17 Warm start sensor
18 Domestic hot water sensor
19 Gas group coding resistor
20 Additional relay (select via D.026)
21 Internal pump
22 Ignition electrode
* Depending on product type
Installation and maintenance instructions ecoTEC plus 0020244998_04