High efficiency water heater

摘要

A multi-stage high efficiency gas fired water heater is provided which includes a lower storage tank and an upper recovery tank around a central flue. Scraping chambers are formed above and below the storage tanks for heat transfer from heated combustion gases. Secondary flues extend through the recovery tank to recover further heat from heated combustion gases. The storage tank acts as a lower volume booster tank from which water at a pre-set temperature may be drawn. Water in the recovery tank is preheated by heat transfer from the combustion gases in the scraping chambers and the central and secondary flues.