In the old days the refrigerator had to be within 4 degrees of level to operate. It was measured on the freezer shelf. Now they just say level enough to be comfortable. I try to get so my head is higher or even than my feet when I sleep. I used a small bubble on the floor near the cab, it was level, then in the middle of the bedroom, it was low in the back, then in the rear bathroom and it was level again. So I figure that I have a slight bow in the middle of the rig.
I'd forgotten about the refrigerator. I knew that it would give a fault code if out of level, so didn't think past that. I just looked in the Norcold manual, it says a max of 3 degrees side-side, 6 deg front-back. So I need to go shop for a level that will help me out with determining degrees. My "bullseye" type just has lines, package didn't say what they indicated.
There's a gold-colored "coin" in the kitchen counter-top: I accidentally discovered that it has the same "level" as the bottom of the refrigerator. Don't know if that's by accident or design.
I always suspected that different parts of the rig could be bowed or torqued, glad to learn someone else thinks so too. I'll go around checking different surfaces for level when my back will permit me to crawl around on the floor.
Thanks for the feedback.
We have the HWH leveling jacks and John (being an engineer) goes by what they say is level. No matter if I say, "Look, all the water in the pan is flowing toward the rear passenger side". His reply "the jacks say we're level". So we go by what the jacks say and if the refrigerator goes into fault mode. So far, so good. There has only been one time when I was concerned the slope would be enough to roll me out of bed but John was happy and the refrigerator was happy so we were "level".
OK, good point: if I roll out of bed, the coach is out of level!

If I had the leveling jacks I'd probably go by what they say also. Probably a guy thing.
We've never gotten the out-of-level fault code on the refrigerator. But sometimes the cabinet latches don't line up. And that can result in causing the catch to pop in so that the door latch doesn't latch; I've also broken a couple (now carry several spares).
I need to do more research on using leveling blocks. On a couple of occasions we had to go 4 blocks high just to get close to level. Fortunately, it was just the front. That would take a lot of blocks to get the back that high; in sites where that would have been needed, we've spent a lot of time angling the rig so that we just needed to raise the front.
Any further opinions/advice, especially on the use of leveling blocks, would be welcome.
Thanks for the replies,
--GeorgeB