Vaillant ecoTEC plus VU 6/5-5 Series Installation And Maintenance Instructions Manual page 69

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)
14 Prioritising diverter valve
15 Water pressure sensor
16 Impeller sensor
0020244997_07 Installation and maintenance instructions
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
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