Water heaters are broadly categorized into gas, electric and solar-powered heaters. Additionally, many manufacturers now offer water heaters that use an electric heat pump called EcoCute. An electric heat pump system uses heat extracted from the air to heat water. It helps to save money on electricity by using nighttime power. This in turn helps to balance the daytime and nighttime power demands for power plants. Hot water is circulated to bathrooms, floor heating systems and so on. The water is adjusted to a temperature specified via a remote controller (CLC communication) by mixing hot and cold water at a mixing valve. Microcontrollers are used for controlling a main unit and a remote controller. A common line communication (CLC) IC is also an essential component. Additionally, a pump motor uses an IPD (single-chip inverter). As is the case with air conditioners, an electric heat pump collects heat by compressing and expanding the refrigerant. A 32- or 8-bit microcontroller with analog functions may also be used. Power factor correction (PFC) ICs or IGBTs are used in the power supply circuit to keep harmonics in the input current below the IEC limit.
