Hello all: COLONEL H here. It's been awhile, but I want to share what I think maybe some time saving info with you.
Bottom line, if you are having an issue with your zoned Aquahot heat exchanger blower fans, do this first.
Check that the fans are wired correctly, i.e. the red (positive) wires from the fans are connected to the positive wires from the system. Same with the negative wires.
I have a 2017.5 Thor Tuscany 38SQ in which the bedroom and living room heat exchanger fans have never worked. After several dealership-service appointments (as the coach is under Warrantee) where they ordered the wrong parts multiple times, I decided to take action myself. (I'm tired of being cold at night)
As a former military maintenance officer for the Armor/Caverlary and having RVed for over 20 years now, I have a bit of experience.
I contacted Aquahot, ordered the correct fans (5 each), they were delivered a few days ago. Today I went to work replacing the first two fans that were diagnosed to be bad. WRONG. They were not bad. They were incorrectly wired. Of the 5 that were supposed to be bad, only one was bad. I replaced it. The others were incorrectly wired.
I corrected the wiring and now all systems are heating perfectly.
I wonder if the dealer service or extended warranty will reembursh me for the fans I purchased?
I hope this helps some one.