Dual mode

Dual mode heating systems combine two different heat generators to meet the heat demand for central heating and/or DHW heating (as opposed to mono mode systems). Dual mode can take the form of "dual mode alternative", meaning that only one of the two heating components is used at any one time, or "dual mode parallel", where simultaneous operation is also possible. The term dual mode is also used in heat pump technology, where it refers to a heat pump and a standard boiler operating in parallel.