Patent ID: 7322532

Claim:
A hot-water supply apparatus having a primary heat exchanger, which absorbs sensible heat of combustion exhaust generated by combustion of fuel, and a secondary heat exchanger which absorbs latent heat of said combustion exhaust, comprising: a temperature detection means that detects a temperature of an inside of said hot-water supply apparatus; a combustion means that supplies said combustion exhaust to said primary heat exchanger and said secondary heat exchanger; an air supply means that supplies air to said combustion means; and a control means that makes said combustion means burn and drives said air supply means based on a detected temperature of said temperature detection means; a freezing prevention temperature that forms reference of a start of freezing prevention operation being set for the control means, and, in case where a detected temperature of said temperature detection means reaches said freezing prevention temperature, said control means making said combustion means burn for a settled time to heat said primary heat exchanger, and driving said air supply means to stream air from a side of said primary heat exchanger to said secondary heat exchanger for a given time after a combustion stop of said combustion means.