I had a 3 KW diesel heater before that did not work at high altitude. I live in Colorado at 6,500 AGL this computer for the 5KW diesel heater is amazing! Lights with no smoke and doesn't take long to get going. I installed mine in a truck topper camper setup. I only use the 1 setting speed and I'm happy.
https://youtu.be/ORKZtXvjs7g?si=YlvLWOvomKLTzRHZ