e-r-a-n:
I will order the relay & Uno rev.3 starter kit.
Can you tell me please which wifi shield will be the easiest to configure and work with?
as i dont know the parts very well, having even a link or specific model will be very helpful
Just be sure to use the heatsink provided in that listing and use good heatsink compound when bolting them together. Many people don't realize that AC SSRs drop about 2vac across their output terminals when conduction and if drawing say 10 amps that is 20 watts of heat to dissipate in the package which would require a large enough heatsink to prevent damage to the SSR. Not sure what the rating for that heatsink is but be sure to check how hot it's getting when it's actually powering your heater load.
Lefty