Can I connect a 2200W boiler without a contactor?

shelly1pm boiler
-
-
With a Shelly 1/1PM it should be possible. Maybe you could make a measurement of the peak-current during switching on the boiler (if you have multimeter with peak-hold function) before.
-
I measured with a tick-ammeter-9A.
-
If this is the peak-current, then there should be no problem to install a Shelly 1PM for switching your boiler.