My Tami 4 is Dead, Again, Part 2

Symptome

6 month after my previous fix, My wather dispenser brocked again, this time the hot water stoped working.

After a vist to the water dispenser dealer, I cam back with a new sensor for the hot water, last time he was rigth, So I give him a try I prurchase a new sensor with a red plug.

mesurement

After a having pluged the new sensor, I did not get any temperature reading, so I made some mesurement:

with the new themo-resistance (red plug)

temp	resistance
0°C	136 K𝛀
25°C	50 K𝛀
33°C	38 K𝛀

with the original themo-resistance (yellow plug)

temp	resistance
25°C	9.68 K𝛀

A single test is enougth to see that the sensor is not the right one.

I also take a quick mesement of the cold wather resistance:

temp	resistance
4°C	24 K𝛀

Check the heating resistor

I also disconnect the heating resistance and check his resistance: 700K𝛀

and check the power sent to the heating element:

Heating state	AC Volt	DC Volt	Amps
Off	1.135V	0V	25 mA
On	10.85V	0V	136 mA

That do not look very promissing...

overview

The system looks finaly preaty easy:

• 1 micro controler
• 1 termo-resistor for Hot
• 1 termo-resistor for Cold
• 1 line en switch on Hot (heating element)
• 1 line en switch on Cold (compressor)

It's look like a simple ESP32 can do the job.