The instruction manual is extremely confusing. The system is advertised as "DIY", but I discovered that it was extremely difficult, and I used to be a master general contractor, handy at most trades. I didn't find out until the system came that the key part of installation - the electrical connections and thermostat hookup and signal wire hookup - must be done by a licensed professional electrician. So, I called in my usual HVAC guy. He was baffled by the manual instructions, I tried to connect to Customer Service at Mr. Cool, but each time the recording said "All agents are helping other customers now. Please leave a message and someone will call you back." No one called back. We are now on the second day of my guy trying to figure out the electrical connections. Maybe we are both just stupid.