Instantaneous water heaters provide hot water instantaneously and only as it is needed. Danfoss offers a comprehensive range of products with different control solutions based on principles of flow, thermostatic, flow and thermostatic or electronic controlling. When you turn on a hot water tap in your home, cold water travels through a pipe into a heat exchanger in the unit. The cold water is heated in the heat exchanger via district heating water or another waterborne heat source. As a result, the water heaters deliver a constant supply of instant hot water.