I once asked a refrigerator manufacturer what “relatively” level really meant and the bottom line is this; if the eggs don’t roll off the countertop or if the blood doesn’t rush to your head while sleeping, the refrigerator will be fine. Still, while standing still, try to get it as level as possible. It’s just not worth the risk in my opinion.
Operating the refrigerator off level creates an inordinate amount of heat at the rear of the unit, especially in the boiler area. Coupled with improper ventilation this extra heat can escalate very quickly into potential costly troubles. When overheating occurs over a period of time, the sodium chromate inside the pipes begins to crystallize (sodium chromate is used to protect the insides of the tubing from the corrosiveness of the ammonia). Typically the blockage will occur in the percolator tube, one of the smallest of the internal tubes inside the cooling core. The percolator tube inside the boiler section can become impassable because of the blockage (see photo). When this happens, the cooling unit is blocked and cannot be repaired. It must be replaced with a new or reconditioned unit.
Leveling is one of the two most important factors to consider when using the RV absorption refrigerator. As mentioned, the other is ventilation. There must be a continuous, chimney-like ventilation space behind the refrigerator all the way up and through the roof. But tell your hubby, as long as he keeps moving he need not be concerned.