I am sorry that you had an unacceptable stay. It is not that uncommon that a problem or damage occurs to an aircondition unit or any other appliance in the house. As I informed you, I replaced both units with new ones immediately after you left the apartment. This was impossible to be carried out while you were still living in the property. I could have fixed the units but I prefered to replace with new ones given that new invertor technology consumes much less electricity. The drain of the washing machine leaked water as someone hit it and it was not properly placed in the drain. All you had to do is to put it back in place ( a 2 second job) and also with regards to the water heater, it was switched off from the switch in the bedroom next to the light switch to enter the bathroom. I am not blaming you but you could have switched it on as you could not have missed it for sure as the switch was right next to the light switch for the bathroom.
I would also like to leave a note on the state of the apartment afetr you (website hidden) seems that you wanted to take some kind of revenge by leaving a total mess. No damage was done but you could have been more tidy.