GAS-FIRED WATER HEATER WITH SEPARABLE HEAT EXCHANGER OR DETACHABLY CONNECTED EXTERNAL WATER HEATER

摘要

A hot water heater, particularly but not exclusively for domestic use, is herein described and having removably secured thereto a modular heat exchanger or an external water heater to heat the water in a separate tank portion. The two are easily separable from one another for service, repair or interchange. The air- to-air heat exchanger extracts heat loss from the central flue of a gas fired water heater to provide a source of heat for the building in which the hot water heater is installed. The external water heater is provided with a gas-fired burner for heating water from the tank circulated in a heat exchanger to transfer heat from a fluid heated by the burner and circulated in the heat exchanger to transfer the heat to water circulated from the water tank.