overrating Fibaro 3kw module (FGS-211)

anyone has some usage experience with overrating a fibaro module ?

i have a water heater in the bathroom which is connected to the light (light is always required in this room so this is not a big deal)
the Heater peaks at 3500 watts …

i want this -z-waved so i can have the always forgotten light turn off, and more important (turn on the waterpump outside the house (also z-waved already))

any toughts …
(please no CE nonsense … i know how electronics work) … :wink: