Remote control for a gas water heater
 

An interesting, if a bit Goldbergesque, way to put a gas water heater on a timer.

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That is a pretty slick way to control the gas water heater, altho the thermostat might not last very long with a device like that, it's hard to say I've never taken one apart.
Another way to do it that might last longer would be to add another valve to the gas line that goes to just the main burner seeing as how the pilot light needs to stay lit.
How my parents control their gas water heater is with a christmas tree light timer, but their water heater has a forced vent and no pilot light, the cost savings from the lack of pilot light can make it worth getting this style of water heater just on it's own.