Vaillant VUW 240/2-3 R1 spark triggered multiple times by Tado V3 Thermostat
Hello everyone,
Hope you are well. I've recently installed Tado V3 Thermostat which is wired (No + COM pins) with boiler Vaillant VUW 240/2-3 R1. Since then I am experiencing following issue:
Temperature gets below the limit - Thermostat switch on the relay which trigger the spark in the boiler and boiler starts heating the water to radiators. Almost immediately I can hear that the spark in the boiler is again triggered multiple times for several seconds, which is not necessary because the first spark already made the fire in the boiler and the water is already being heated.
I have never had such issue with my old thermostat which also used simple relay. It triggered the spark, spark caused fire and fire heated the water.
Any idea why thermostat is triggering spark multiple times?
Below is picture of my wiring - currently I have two wires connected to 3 and 4 pin in my boiler.
