Do I need another boiler as a back-up?

Many situations require one or more back-up boilers, especially those involving residential accommodation. A properly designed and installed biomass boiler will be as reliable as a fossil fuelled boiler, and in this respect the usual rules for specifying back-up boilers should be applied. However, as a biomass boiler is rarely sized to meet the peak load, the back-up boiler usually acts as a peak-topping boiler as well. Hence, it is usual for back-up boilers to be sized to meet the peak load.