Since it is a gravity fed, most likely you have a kinked hose between inlet and tank. Maybe there is a check valve, but doubt it. A least you have an appointment tomorrow and not in a week or more.
2011 Rockwood 8319SS with ProPride 3P hitch/GoodYear Marathons/TST TPMS 507
2008 F250 Lariat CC SB 6.8L V10 4.10 axle ratio (NITTO TERRA GRAPLER G2 LT275/65R20E)
Yamaha 3000iseb generator:Progressive Ind. EMS-HW30C : Eastern Ontario
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