... But unless the unit states that it can be layed on its side OR you get written consent from the Mfgr., you're probably taking matters into your own hands.
At the same time, one thing that probably most prevents you from laying it on its side is the dip tube. Granted I don't know anything about trailer units, but if the unit is layed on its side, the dip tube would only suck about 1/2 of the water in the tank. The tube is meant to be VERTICAL.
Maybe someone can say for sure but if not, ctc. the Mfgr. for info. (And no matter how you get authorization, be SURE to get it in writing!)
My best to ya and hope this helps.
Jay J -Moderator
PS: Other than having to spend some $$$, why don't you have a unit that's 'properly SIZED' for the allocated space, where one doesn't have to be layed down to fit?