I have had this problem with every rig I have owned, what I ended up doing is taking metal flashing and making "trays" for the closes registers-turn on furnace/fan and check airflow. If your 2 farthest registers have enough air then reinstall all the registers, if to much from those registers then start with the next farthest ones and start adjusting.
Hi I've got a 2015 rockwood 8289 ultra lite and had the same problem, I tried electric heaters but kept tripping the site so I spent £2500 and installed a wood burner
Just love it!! And the slides close without any problems? If you said this was a 1960 something trailer that you resurrected..ok. But a brand new one. I'm still looking for the socks you just knocked off.
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