Black Tank Flushing System

Anne & Erik · 03-16-2008, 06:42 PM

We have a 2006 Itasca Horizon. Recently, the black tank flushing system ceased working. We screw the hose system into the unit, but no water is allowed to flush through the system.

I have heard there were tank problems with this era Winnebago/Itasca. Anyone ever heard of this problem? As far as I can tell, the "cure" would involve dropping the tanks, which would be very costly.

Anne & Erik

Anne & Erik · 03-16-2008, 06:42 PM

We have a 2006 Itasca Horizon. Recently, the black tank flushing system ceased working. We screw the hose system into the unit, but no water is allowed to flush through the system.

I have heard there were tank problems with this era Winnebago/Itasca. Anyone ever heard of this problem? As far as I can tell, the "cure" would involve dropping the tanks, which would be very costly.

Anne & Erik

jimandsue60 · 03-16-2008, 06:54 PM

The check valve where you screw the hose into the black tank flushing system is faulty. The check valve will need to be replaced or possibly reset. Sometimes high pressure water will move the check valve far enough to not let it reset. This is a very easy repair or replacement depending on access to the back side of the connection.

I have to do the same to my rig due to a very high pressure water system that I hooked up to the flushing system.

I happen to have a spare and will take pictures of the job while I do it.

JIM

Anne & Erik · 03-16-2008, 07:06 PM

Wow. That makes sense. The water source we just hooked up to was pretty high pressure. Is this something I can do without dropping the tanks?

Anne & Erik

jimandsue60 · 03-16-2008, 08:09 PM

No you should not have to drop the tank.

The check valve is physically behind and attached to the inlet for the tank flusher. If you can, position your hand behind the flusher to see if you can touch the back side of the flusher.

If you are not a mechanical type person this job might be better suited to some one that is an rv technician.

Jim

SCVJeff · 03-17-2008, 10:32 PM

I have a valve at the hose input of mine so I have local control. More than once I have had that check valve close if I open the hose valve too fast. Kind of like some propane check valves.

Maybe if you start out slow it'll behave?

DancinCampers · 03-18-2008, 10:22 AM

I guess Winnie made a change. My unit does not have a check valve on the black flush inlet. Mine goes thru a vacume backflow valve under the bathroom sink. When I remove my hose the water between the vacume valve and the hose connection runs out.

I noticed that on the Horizon plumbing diagrams they also have the vacume backflow valve. Not sure why they would have both, unless to double your trouble.

NoMoreAZ · 03-19-2008, 03:47 PM

Exqueen, what model 06 Horizon do you have? The check value may not be located where other replies have told you. You will notice I have a 40KD. The chkeck valve for the black tank flush system on a KD is located a couple of feet up the line from the flush H2O intake. On a K, if you open top right drawer in the bathroom you will see two pieces of PEX. At the top is a metal vacuum breaker valve assy. Plugged into that is the plastic check valve assy for the black flush line.

The fresh H2O inlet has the check valve directly behind it. Is so on my K, was also true for fresh H2O inlet on my 05 Adventurer 35A.

PORCHDOG · 03-20-2008, 04:08 PM

I hooked up to my flush and it plugged up while I was flushing my black tank. Here in Florida we have lizards crawl into water hoses to hide. I did not know it at the time but that is what happened to me and the lizard was forced into (and through)the tank flush nozzle by the water pressure. I was able to disconnect the nozzle to the tank and clean it out with a wire. Since then I keep a strainer attached to the hose washer in that fitting. I think they make them for washing machine hose inlets.