Cold-fill washer machines are characterized by the absence of a hot water valve. Advantages of cold-fill washing machines include being more energy efficient, better wash results with biological detergents and lower prices stemming from a cut in manufacturing costs.
Cold-fill washing machines are more energy efficient because they do not pull hot water from a boiler and hot water tank plumbing system. Instead, cold-fill machines use cold water to flood the unit and heat the water once it is inside the washing bowl. This reduces the need for the boiler to continuously run and reheat water. This significantly reduces energy costs. Furthermore, hot water drawn from a boiler does not always make it to the washing unit. This means that there is hot water wasted in the plumbing when using a hot-fill machine.
A cold-fill washing machine is also more efficient when cleaning laundry using a biological detergent. The optimum temperature for the enzymes found in biological detergents is 40 degrees Fahrenheit or below. Water that is hotter may kill the enzymes.
The reduction in the price of manufacturing a washing machine unit without a hot water valve, a hot-fill hose and the numerous other parts that compose a hot-fill washer, is passed along to the consumer, which makes these units cheaper.