Control method of central gas water heater

Abstract

The invention discloses a control method of a central gas water heater. The control method is characterized in that in the preheating process, when a water inlet temperature sensor arranged on a water inlet pipe detects that the water return temperature is equal to the set temperature of the water heater, a master controller controls a combustor to stop combustion, and a circulation water pump is controlled to continue to operate for water pump posterior circulation; and when any of the following conditions is met, it is judged that a user is bathing, and the circulation water pump is shut down, wherein (1) in the water pump posterior circulation process, when the water inlet temperature sensor detects that the water return temperature is lower than the set temperature of the water heater by T DEG C, 5 DEG C<=T<=10 DEG C, and (2) when the operating duration time of the circulation water pump exceeds 30 min, water pump posterior circulation is not executed. According to the control method, whether the circulation water pump enters posterior circulation in the preheating process or not is used as the judgment basis, whether the user utilizes boiling water in the preheating process or not is judged, interference is prevented from being caused to the preheating stop condition, water temperature fluctuation brought by circulation water pump operating during bathing is avoided, and the bathing comfort of the user is guaranteed.

Description

technical field [0001] The invention relates to the technical field of gas water heater control, in particular to a control method of a central gas water heater. Background technique [0002] In recent years, various gas water heaters with no return pipeline and preheating function have appeared on the market one after another, realizing the instant heating function of gas water heaters to a certain extent. However, in order to ensure the uniformity of water temperature in the pipeline, many water heaters of this type generally have a long post-pump cycle (during the preheating cycle, after the burner stops working, the water pump continues to work for a period of time), and the longer the burning time of the water heater Longer, the corresponding water pump cycle time is longer, so the following problems will occur in the actual use process: the water heater has not heated the water in the pipeline to the required temperature, or the user boils the water before the water pu...

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Problems solved by technology

However, in order to ensure the uniformity of water temperature in the pipeline, many water heaters of this type generally have a long post-pump cycle (during the preheating cycle, after the burner stops working, the water pump continues to work for a period of time), and the longer the burning time of the water heater Longer, the corresponding water pump cycle time is longer, so the following problems will occur in the actual use process: the water heater has not heated the water in the pipeline to the required temperature, or the user boils the water before the water pump cycle is stopped. At this time, the water heater cannot effectively judge whether it is in the bathing state or the preheating state, because the temperature of the water inlet probe has not reached the preheating shutdown temperature, and there is a phenomenon that the water heater continues to burn after the user finishes using water.

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