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Mitsubishi PAC-US445CN-1


Hi everyone! Please bare with me as I try to explain my situation. I recently installed a Mitsubishi SVZ air handler with the SUZ hyper heat condenser. I used the MHK2 thermostat and kumo cloud adaptor. Now before I did the install I called mitsu tech support and explained what I was doing. I ripped out a gas furnace and put this AHU in with the EH05 electric strip heater. The customer had a T-9 thermostat and a bunch of room sensors that he would occasionally change what room is controlling the system. Mitsu tech support said I can do the same with their room/humidity sensors so I bought 4. After the install everything is running, I try to connect the room sensors and it won’t let me. I called tech support back and talked to someone different and they said I can’t use room sensors with the mhk2. I can use one sensor and one only if I take the mhk2 out.

So that brings me to today. I pick up the PAC-US445 so I can reconnect his T9 and room sensors. He’s ok with losing some fan modulation because the T9 only had one fan speed and the PAC-US445 has 3 G terminals. My question is how does the system control the electric strip heater? The PAC-US445 has two stages of heat and two stages of cool. I’m going to wire them both up. Is W2 the heat package? Or does the system know when to control the heat strip based on temperature drop between indoor temp and set point? I called Mitsubishi and asked but they couldn’t tell me because the T9 is not their product.

If anyone has any tips for the PAC-US445 I would greatly appreciate it! I did read that I need to set the T9 up as regular forced hot air not a heat pump because there’s no O/B terminal on the PAC-US445.


  • GW
    GW Member Posts: 4,734

    I've never installed a thermostat adapter on Mitsubishi, you lose too much functionality and diagnostic feedback. This is a deeper dive, maybe there's someone here that does this and knows the answer. Your local Mitsu rep/TM can't help you? Good luck

    Gary Wilson
    Wilson Services, Inc
    Northampton, MA