Grey/Black Dump Valves

[Mullins]

When we started RVing we were told to leave the grey and black dump valves closed until we pack up to leave then open the black first then the grey; which I do then I flush the black tank. But I am wondering if there is anyone out there who has or do leave the dump valves open while they are camped or lat least experimented with the idea. is there any benefit one way or the other? And of course this would be at a full hook up RV Park.

 

[branson4020]

Unless you want to experience the dreaded brown beehive of doom, do NOT leave the black tank valve open.

 

[Lynn1130]

More specifically, leaving the black valve open allows the fluids to drain out and the solids to pile up in a pile that hardens and is near impossible to remove. You can leave the gray open but a day or so before you pack up close the gray and use that water to flush the lines after opening and dumping the black.

 

[danemayer]

All good advice. You can find some additional tips and techniques in our owner-written Water Systems Guide.

 

[Gizzy]

Leave the black tank valve closed and use LOTS of water each time you flush.