Gas water heaters do not require electric power. There are no wires to connect. The spark to light the pilot is a piezoelectric thing, manually operated. Newer

Gas water heaters do not require electric power. There are no wires to connect. The spark to light the pilot is a piezoelectric thing, manually operated. Newer models (less than ~15 years?) have a control board which is probably mostly mechanical, but does have a flashing LED. I assume that whatever drives the electronics is charged/powered by something that works off the differential of temperature in the chamber vs outside.