Is there any sort of annual maintenance that I need to do on a gas water heater? How? I live in Indiana and this entire state sits on a bed of limestone (calcium carbonate) that dissolves into the water. I'm asking because I need to remove the lime build up on the coils of our small portable room humidifier about 2 or 3 months. Do I need to do something similar to the water heater? My wife believes that the water heater does not produced enough hot water (I think it's fine). I've got the temp set at 2/3 on the dial. The water heater is about 7 years old. We are not really having a problem, I'm just asking about preventative maintence. Thanks.