I am new to the arduino world and I am looking for a way to automate the temperature in my gas water heater. I want to use an arduino to turn the knob on my water heater from high to low during times I do not think anyone will use the shower. Then have it turn it up during hours where I believe the water will need to be hot.
Any suggestions? I read a servo might work but I am not sure how I would attach it to the arduino and then attach something to it to turn a knob. I am not sure what kind of arduino I would need, how to hook it up and program it.
My water heater knob looks like this - http://www.danoah.com/wp-content/uploads/water-heater-temperature-knob-585x390.jpg
Any help is appreciated.