There may be several possibilities: 1, the water heater is broken, and where it is broken depends on the performance. Maybe the sensor is broken, maybe the controller is broken.

2, the problem of water heater setting, the water heater you set requires a relatively high temperature, and the heating mode you set has always been heat preservation. In this case, the water heater needs to be heated to a higher temperature first, and then heated once it is lower than this temperature. So the performance is always heating, and the actual situation may be that the heat preservation time is very short. Not easy to feel.

3. Carefully study the setting links in the manual, which should solve the problem.