Greetings.....I just had to start a thread for my gray water tank macerator pump issues. This is a 2011 Via 25Q. We purchased used this past December. All seemed great on the dealers lot but we quickly discovered the gray tank would not empty..
. Yuck....With the Q series the macerator pump is located on a back wall about 30" behind the water valve panel and another 30" below the queen bed platform. Talk about difficult access!!!!! It's intake is above the 1/2 full point on the gray tank yet with the tank failing to drain the shower all we could get is a trickle. Best option to empty tank was to remove the 1-1/2" threaded plug on the gray line and work the slide valve to decant the tank in 5 gallon portions into a large pail.
Removal of the macerator pump took about 3.5 hours and required disassembly of the metal partition wall between the electrical bay and water management panel just to access the mounting screws that hold this pump to the rear panel. Undoing the band clamps that held the lower pump FERNCO intake fitting to the ABS piping required lowering myself to the hips through an access cover under the queen mattress platform. The Flexible 1" PVC discharge hose needed to be cut with a PVC cutter as even with its band clamp removed it was impossible to separate from the macerator pump in that tight space.
Upon teardown of the pump I find that likely a drain cleaner or winterizing fluid left in the pump caused a complete melt down of the pump impeller. It looked like a wad of green goo inside the pump body (see photo).
I ordered a rebuild kit with impeller and gasket from Amazon and rebuilt the pump. Hope I did correct but remounted the pump to an outside surface of the water service bay box that had plenty of room behind the gray tank to repipe and much easier service access. The location is protected from water and road debris and allows for complete drainage of the gray tank and piping when winterizing the RV.