It can't be heated after being electrified, probably because the power board doesn't work and doesn't provide power voltage to the computer control board; Or the control panel is not normal. Visually inspect the power board and control panel, and check whether all components, connecting wires and power board work normally. Pay attention to whether there is electricity when checking!
This is caused by a fault in the thermostat circuit. When the main thermostat (about 100 degrees Celsius) senses the highest temperature, the main heater should be turned off and the insulating heater should continue to work. Now you only have heat preservation and no heating. It must be a thermostat failure or a heater failure.