- Both gas and oil water heaters use burners and a combustion chamber located at the bottom of the water-holding tank to heat water. These two systems have preset heat limits working with a thermostat monitoring when the water temperature goes below 50 degrees. When the sensors of the thermostat register the low heat level of the water in the tank, the gas burner flame catches from the pilot light; with the oil burner, a jet-flame ignites in the combustion chamber. Both systems burners heat a copper core running through the tank from the bottom up which in turn heats the water surrounding it.
- The measure of how many gallons of water heats in an hour (from 50 to 100 degrees Fahrenheit) is the recovery rate. Typically, oil-heated water systems provide the most heat with the fastest recovery time over gas systems. Since both these fuel-fired systems have higher recovery rates over other systems (an electric water heater for example), large-capacity water heater tanks are not necessary.
- Detecting warmth when touching the jacket of either tank (gas or oil water heater) calls for an outer insulation blanket. This special cover prevents heat loss and reduces fuel cost for both oil and gas water heaters.
- Yearly maintenance by qualified professionals keeps destructive sediment out of both gas and oil hot water heaters. Ridding the tank of sediment keeps the glass lining of the water tanks from breaking down. Compromised glass linings leads to weakening of the steel and the need to replace the entire holding tank.
- Because of the danger of life-threatening carbon monoxide poisoning, installation of both oil and gas water heaters in sleeping areas is against the law. Water heater installation in a garage must be 18 inches off the floor to prevent igniting gasoline fumes. At the same time, garage-installed water heaters must have protective barriers against accidental vehicle collision with the unit.