Selecting the best propane water heater is dependent upon your household needs. Standard heaters are available in tank sizes ranging from below 40 gallons (151.4 liters) to over 100 gallons (378.5 liters) but energy-efficient tankless models are gaining in popularity as prices drop. A tankless propane water heater requires less space and saves on long-term heating bills, but the initially low price of a standard propane water heater attracts many buyers.
Standard propane water heaters utilize a holding tank that keeps water at a constant temperature regardless of use. A heating element is located in the bottom of the tank, holding the water at the temperature determined by a thermostat setting. The constant heating process leads to high energy use and considerable inefficiency. The heaters have remained popular because propane has traditionally been a relatively low-priced fuel.
This type of water heater is also attractive to those on a restricted construction or remodel budget, as the unit is approximately half the price of a tankless heater. Standard heaters hold the advantage of being a known quantity, as they have been in use for decades. Many buyers, and some contractors, are still uncomfortable with the idea of the relatively new tankless technology.
A tankless propane water heater provides hot water on demand, just like a standard heater. The difference is that the water is heated only when the valve on a faucet, shower or tub is opened. The unit senses an open valve, ignites the propane, and heats coils through which water flows prior to moving toward the faucet. A tankless heater is in fact a type of heat exchanger, and water is heated almost instantaneously. Hot water arrives at the faucet just as quickly as with a standard water heater.
A tankless propane water heater is superior in most every way over a standard tank heater. It is energy-efficient, small and saves enough fuel to pay for itself in less than a year. It can be mounted almost flush with a wall, in contrast to the large, stand-alone tankless heaters that require a good deal of installation space and outdoor venting.