Patent ID: 7534306

Claim:
A method of removing scale from a heat exchanger of a steam humidifier, said steam humidifier having a gas burner with a forced air flue, said steam humidifier having a canister holding water to be evaporated as steam, said canister having an upper canister part and a lower evaporator part, a combustion chamber disposed in said canister, said gas burner disposed within said combustion chamber and mounted in said upper canister part, a heat exchanger disposed within said canister and configured as a coiled chamber with spaced apart loops, said heat exchanger coupled downstream of said combustion chamber and said gas burner, the method comprising: immersing said combustion chamber within which is disposed said gas burner in said water of said canister, draining the water from said canister, creating a thermal shock on said heat exchanger without water in the canister, said thermal shock resulting from activation and then deactivation of said gas burner, wherein both said activation and deactivation occurs without water in the canister, said thermal shock causing thermal expansion and contraction of said coiled chamber heat exchanger to remove scale adhered thereon.