Freestand filtered refillable water cooler dispenser freezes water

Dear Expert

I have got my old Standalone filtered refillable water cooler dispenser freezes water in the reservoir means tap for the cold water won't dispense water.

The company called Aqua port which is acquired by Breville,

My model is not exist any more and no spare parts

I have another cooler exact same model I got it to be used as spare parts

When the problem of freezing started I thought problem with the cold thermostat sensor _,I swapped between the cooling sensor and heating sensor(always off) same problem persisted

Then I swapped the sensors from the spare part one to my one and still the same problem.

I haven't touch the adjustable screw for the cooling thermostat.

Manual for my cooler in the below link :

https://2ecffd01e1ab3e9383f0-07db7b9624b...

Page 9 says :

3. If the cold thermostat has been adjusted then this may cause the unit to over cool

and freeze. Reset back to factory setting. If the thermostat has not been adjusted Call

customer service

Photos showing ice in the reservoir

https://imgur.com/a/BJ33PLz

Thx