Item (#93)
| Type | |
|---|---|
| Brand | Panasonic |
| Model | - / - |
| Serial | - |
| Colour | Ivory |
| Description | The thermal pot temperature preset functions failed. The pot continue to boil water to 100 C and could not preset to desired temp like 60, 80, 90, 98. |
Other repairs
Repair (#98)
| Status | Repaired |
|---|---|
| Location | Yuhua |
| Date | 22 April 2026 |
Faults
No common faults selected
Problem description
The thermal pot temperature preset functions failed. The pot continue to boil water to 100 C and could not preset to desired temp like 60, 80, 90, 98.
Photos
Repair Notes
1 In this case, the possible faulty components: microcontroller( located at the upper part of the pot), thermistor( a transparent tiny tube pressed against the bottom of the pot; relay, a small black box (located at the base pcb board)
2 The working principle for these 3 components: the thermistor changes its resistance as temperature changes, as water gets hotter, the resistance drops. This varying voltage is sent to the microcontroller. The microcontroller is the brain, reading the data from thermistor . The thermistor ‘s resistance corresponding temperature is 75 degree, but user wants 90 degree. The microcontroller cannot power the heater directly because the heating element needs 230V , while microcontroller only has 5V. Thus relay , the muscle comes into place. The microcontroller sends 5v signal to the relay. The signal creates a magnetic field that open and close a metal switch which in turn control the on/ off of the heating element.
3 To check the relay, it has 2 steps,a) try to bring a 9v battery close the legs, you can hear a click sound, meaning the relay creates a magnetic field. b)use multimeter to measure the resistance of the relay, it should be between 50-200 ohms.
4 I also took out the thermistor ,it is a bit difficult to test . I check the resistance of the thermistor by bring a heated soldering iron close to it, the resistance drops and the thermistor should be good .
5. As for the microcontroller, because it should have built in program inside, there is nothing I can do about it.
6. After following the label of the relay, I bought the same one and soldered it back to the pcb board and the thermal pot can work again by setting the desired temperature.
there are a few common culprits for why the temperature cannot reach a set point, for example, thermistor, relay