As stated, call the manufacturer and ask, to be sure. .....And ask
I've always understood, though I've never known for sure, there's some
sort of thick oil reservoir (or something), built in, and if turned to
the side for a long period, this reservoir oil will screw up,
somehow. Turning it on the side for a short time, is somewhat okay,
but once upright, again, you have to let the oil settle again, in its
"proper place", before using the machine... allow a day or so before
use. For long term side position, it takes a lot longer for the oil
to settle/return properly, hence allow a longer period before use.
I've understood this applies to refrigerators, also.
Again, I don't know if this is so, for sure. That's the way it was
explaind to me long ago, as to why you don't turn units on their
sides. Maybe this applied to much older machines, not today's