A boiler, or a hydronic heating system, uses a fuel source to heat a fluid – usually water or glycol – which is then pumped through your hydronic heating system to various devices such as radiators, in-floor heating loops, air handler, etc. to heat your home. A boiler can also be used as your home’s hot water heater, providing hot water for your kitchen, bathrooms and clothes washing, as well as for other forms of heating. Boiler heat does not require ductwork and can often be found in older homes