Check fuse F14 on the house interior fuse panel. It's the second one from the bottom, on the right-hand side of the panel. It's a 10A fuse. Fuse F14 powers the water pump and the tank monitor system.
If your coach is like ours, then the interior fuse panel is in the bedroom, on the driver-side wall above the window, next to the 120V breaker panel.
2008 Holiday Rambler Admiral 30PDD (Ford F-53 chassis)
2009 Honda Fit Sport