AIR INTRUSION DETERMINING METHOD OF HOT WATER HEATING SYSTEM

PROBLEM TO BE SOLVED: To provide a determining method capable of surely determining the occurrence of intrusion of air, and capable of avoiding the occurrence of erroneous determination as the occurrence of water leakage, by sharply distinguishing the occurrence of intrusion of air and the occurrence of water leakage, in a hot water heating system. SOLUTION: Heating operation is started (S1), and when detecting lowering of a water level up to being less than a preset low water level by an OFF change of an electrode L (S2 YES), when it is within lapse of 10 min from starting heating operation, it is added to an air intrusion determining counter L, and is determined as the occurrence of intrusion of air when it becomes two times, to perform falling-water processing (S5 NO, S10, S11 YES, and S12). Before 64H pass from last time water supply after 10 min pass, it is added to a water leakage determining counter N. When it becomes two times, it is determined as leakage of a small quantity (S5 YES, S6 NO, S13, S14 YES, and S15). Water is supplied up to ON of an electrode H by opening a water supply solenoid valve after 64 H pass (S7, S8 YES, and S9). When the electrode H is not turned on even if 2 min pass after starting water supply, it is determined as leakage of a large quantity (S8 NO, S16, and S17). COPYRIGHT: (C)2005,JPO&NCIPI