I bought this brand new heater a few days ago, when I put my multimeter to the wires to test the resistance, I got infinity. What the hell!
Here is how I fixed a brand new heater.
Step 1: The Heater.
This fame Ducha is popular in my country. Very safe once properly grounded. Time to make it ready for installation.
Step 2: Opening the Top.
A flatblade I used to take off the top. Now the switch for hot off lukewarm is exposed.
Step 3: Removing the Switch.
5 Phillips head screws hold the switch in place. Once removed the switch assembly comes off.
Step 4: Verifying the Heater Coils.
I measured the hot and lukewarm coil resistances. These values are expected.
Step 5: Fixing the Contacts.
The spring contacts were not touching their corresponding contacts. This is supposed to be a safety design that allows the heater to be on only when the water pressure is present. For high current switching this arrangement is not ideal and can easily cause arcing plus pitting of the contacts. I want a proper direct connection. Also I made a heater control panel that turns off the heater if no motion is detected inside the shower. Safety wise I'm better covered with my motion sensor system that has been working perfectly for the past 3 years.
I pulled the spring contacts out to ensure low resistance mating.
Step 6: Reassembly and Testing.
Ah ha. Now the leads give a reading per hot and lukewarm settings. Perfect.
Step 7: Completion.
The lid is back on and the heater ready to be installed!