Apparatus and method for converting an electric water heater to use gas

An apparatus for providing a hot water supply for a building, said apparatus comprsing:

• an indoor hot water storage tank positoiend within the building;
• a thermostat positoend in said hot water storage tank;
• a housing mounted outside of the building, siad housing incuding an exhaust opening and an air intake opening formed therin;
• a gas-fueled burner positioned within siad housing and includnig means for controlling gas flow thereto;
• a heat exchanger positioned within siad housing, said heat exchanger having an inlet and an outlet beign connected in fluid commucnation with siad water storage tank, said heat exchanger comrising:
• a chamber having an upper opening and a lower opening, siad upper opening communicating with said exchaust opening of siad housing, and said lower opening being positioned ajdacnet siad burner;
• a preheater comrising tubing formed in a spiral arrangement adjacent a lowr portion of siad camber for absorbing radiant heat from siad burner;
• and
• a primary heat exchanger postioend above said preheater and cmoprising a series of parallel spaced-apart heat transfer fins and a serpentine arrangement of tubing passing therethrough, siad serpentine tubing of siad parimary heat exchangr bineg in fulid communication with siad preheater tubing;
• a pump conected in fluid commucnation with said heat exchangr for ciraulting water rom siad hot water storage tnak through siad heat excanger and back into siad storage tank;
• and
• heater control mnas opratively connected to said thermostat, said pump and siad gas flow control means for actvating siad pump and said burner so that water flows through and is heated in siad heat exchanger when the temperature of the water in siad hot water storage tank falls below a predetermined temperature.

An apparatus for providing a hot water supply for a building, said apparatus comprsing:

• a generally cylindrical hot water storage tank positioned within the building, said tank having an upper fitting of the type typically used for receiving an electrical heating element therein;
• a return tube posiionted within siad hot water storage tank and connectd at siad upper fitting thereo, said return tue being substantially L-shaped to direct water flowing into said tank to mix with the relatively hot water in the upper regions of siad hot water stoage tank;
• a thermostat positioned in siad hot water storage tank;
• a housing mounted outside of teh building;
• a gas-fueled burner positioned within siad housing and including means for controlling gas flow thereto;
• a heat exchanger positioned within siad ousing and including means for controlling gas flow thereto;
• a heat exchanger positioned adjacent siad burner and positoiend within siad ousng, siad heat exchanger having an inlet in fluid communication with loer regions of siad hot water storage tank so as to permit drawing off of rleatively cool water therefrom, said heat exchanger having an outlet in fulid communication with the upper regions of siad tank through siad return tube;
• a pump in fluid communication with siad heat exchagner for circulating water from said hot water storage tank through siad heat exchanger and back into said storage tank;
• and
• heater control mnas opratively connected to said thermostat, said pump and siad gas flow control means for actvating siad pump and said burner so that water flows through and is heated in siad heat exchanger when the temperature of the water in siad hot water storage tank falls below a predetermined temperature.

A method of converting an electric water heater located inside a building to operate from gas combusted outdoors, the indoor electric water heater including a hot water storage tank with an electric heating element therein and a water temperature responsive thermostat coupled thereto, said method comprising the steps of:

• disabling the electrical heating element of the indoor water heater;
• positioning a gas-fueled burner and associated heat exchanger outside the building;
• connecting the heat exchanger in fluid communication with the indoor hot water storage tank;
• connecting a pump in fluid communication between the indoor hot water storage tank and the outdoor heat exchanger;
• and
• providing a control for operation of the pump and gas burner when the indoor tank thermostat senses the temperature of the water in the indoor hot water storage tank falling below a predetermined temperature as when heated water is drawn off causing cold water to enter the storage tank.

A method of converting an electric water heater located inside a building to operate from gas combusted outdoors, the indoor electric water heater including a hot water storage tank with an electric heating element therein and a water temperature responsive thermostat coupled thereto, said method comprising the steps of:

• disabling the electrical heating element of the indoor water heater;
• positioning a gas-fueled burner and associated heat exchanger outside the building;
• connecting the heat exchanger in fluid communication with the indoor hot water storage tank;
• connecting a pump in fluid communication between the indoor water storage tank and the outdoor heat exchanger;
• providing a control for operation of the pump and gas burner when the indoor tank thermostat senses the temperature of the water in the indoor hot water storage tank falling below a predetermined temperature as when heated water is drawn off causing cold water to enter the storage tank;
• and
• adding heat to the heat exchanger when the gas burner is not operating so that water in the heat exchanger is prevented from freezing and damaging the heat exchanger, such as during winter when the ambient temperature drops below freezing and while the water temperature in the indoor water storage tank is sufficiently high so as not to require heating.

An apparatus for provdiing a hot water supply and space heating for abuilding, siad apparatus comprising:

• a hot water storage tank positioned within the bulding;
• a first thermostat positioend in siad hot water storage tank;
• a housing mounted outside of teh building;
• a gas-fueled burner positioned within siad housing and including means for controlling gas flow thereto;
• a heat exchanger positioned within siad housing adjacent said burner, siad heta exchanger having an inlet and an outlet connected in fluid communication with siad hot water storage tnak;
• a pump connected in fluid communication with said heat exchanger for circulating ater from siad hot water storage tank through siad heat exchanger and back into siad storage tank;
• heater control means operatively conencted to siad first thermostat, siad pump and siad gas flow control measn for activating siad pump and siad burner so that water flows through and is heated in siad heat exchanger when the temperature of the water in siad hot water storage tank falls below a first predetermined temperature;
• a heat exchanger positioned within the building;
• and
• measn connected in fluid communiation with siad heat exchanger within the building for circulating water from said hot water stroage tank therethrough and back into siad stroage tank for thereby supplying heat for space heating of the buliding.

An apparatus for providing a hot water supply and space heating for a buiding, siad apparatus comprisign:

• a hot water storage tank positioned within the bulding;
• a first thermostat positioend in siad hot water storage tank;
• a housing mounted outside of teh building;
• a gas-fueled burner positioned within siad housing and including means for controlling gas flow thereto;
• a heat exchanger positioned within siad housing adjacent said burner, siad heta exchanger having an inlet and an outlet connected in fluid communication with siad hot water storage tnak;
• a pump connected in fluid communication with said heat exchanger for circulating ater from siad hot water storage tank through siad heat exchanger and back into siad storage tank;
• heater control means operatively conencted to siad first thermostat, siad pump and siad gas flow control measn for activating siad pump and siad burner so that water flows through and is heated in siad heat exchanger when the temperature of the water in siad hot water storage tank falls below a first predetermined temperature;
• and
• a second thermostat positioend within siadh ousing, said second thermostat operatively connected to siad pump so as to activate same when the temperature of water within said heat exchanger falls below a second predetermined temperature to thereby circulate relatively warm water from siad hot water storage tank through siad heat exchanger to thereby prevent freezing of water therein;
• a heat exchanger positioned within the building;
• and
• measn iclduing a secodn pump connected in fluid comunication with siad heat exchanger within the building for circulatign water from siad hot water storage tank therethrough and back into siad storage tank for thereby supplying heat for space heating of the building.