Instant on tank-less water heaters are a good step on energy efficiency and emissions reduction. There are a couple of tricks, it is best to be 'pilot-less' and

Instant on tank-less water heaters are a good step on energy efficiency and emissions reduction. There are a couple of tricks, it is best to be 'pilot-less' and the other is the gas line usually has to be larger, so it isn't always a drop in replacement. This is due to it having to heat the water quickly using a higher amount of gas while running.