I purchased a Fairfield 403 BH new last spring. Its permanently parked at a sight with full services. I like the rig but draining the black water tank has been a challenge since day 1. Typically I drain the back then flush it several times every time we use it and the tank will still not be empty (which I know from looking down the toilet as opposed to relying on the gauges). I have tried to snake the line to see if there is any obstruction maybe from the manufacturing process but have been unable to find anything. I have used a couple of different chemicals and we use the RV toilet paper. I am wondering if the tank to could be unlevel (the trailer is level). I know there are many threads on this and I have tried a number of solutions. The other challenge is that the trailer is not really moveable now so I can't bring it back for service. Appreciate any comments or if someone else has the same rig if they have any issues. Thanks.
Fairfield Destination Trailer dump problem
- Thread starter ScottD
- Start date
danemayer
Well-known member
Hi ScottD,
I'm not sure what you mean when you say "the tank will still not be empty." Do you mean there's nothing coming out the sewer outlet but you can still see some water in the tank? Or perhaps you mean there are solids built up that aren't coming out.
You might want to take a look at our Water Systems Guide. The section on dumping tanks starts on page 17 and continues for a few pages. Page 20 gives tips on clearing stubborn blockages.
After you dump the black tank, you want to add 5 gallons or so of water back in so that solids dissolve in a nearly empty tank. If the tank is completely dry you will get solids built up on the bottom of the tank and will find it difficult to get them out. It's also a good idea to use a lot of water when flushing solids. Sometimes people try to minimize the water flushed for various reasons, but that also leads to difficulty when draining the tank.
Appreciate the reply, normally I fill the tank several time with the tank flush system to build up some pressure. I get an initial rush when I pull the valve but then is slows to basically nothing and I can see the tank is still not empty. We are permanently hooked up so I always encourage lots of water use to avoid this problem. I'll have a look at the clearing blockages threads and try some of those once we get back out to the campground.
danemayer
Well-known member
Mine sometimes does this: initially there's a lot of water coming out, then it slows to a trickle. That happens because there's a clog at the outlet. If you close the dump valve while there's material clogging it (even a little), it creates a slow leak because paper/stuff gets compressed into the valve seat. After that, the water you flush during normal use leaks out and solids build up. It becomes progressively more difficult to get the tank clean.
I've experienced this and it took many tankfuls of water to get the valve clean again. I'm now very careful to very thoroughly drain/flush/drain/flush/drain/flush the tank before closing the valve.
I've experienced this and it took many tankfuls of water to get the valve clean again. I'm now very careful to very thoroughly drain/flush/drain/flush/drain/flush the tank before closing the valve.
Ray LeTourneau
Senior Member - Past Moderator
Scott, when you say you cans "see" that there is still water in the tank, are you referring to the tank level light indicators? These are historically inaccurate. Even when the tank is empty, it still can indicate otherwise.
Do you use this trailer mostly on weekends? If so, consider not dumping the tank until it's actually full. We can go about 10 days before ours is ready to go. You'll get a better siphoning action if the tank is full.
Do you use this trailer mostly on weekends? If so, consider not dumping the tank until it's actually full. We can go about 10 days before ours is ready to go. You'll get a better siphoning action if the tank is full.
I too was experiencing difficulty draining my black tank. I found the plastic disc created when the hole is cut for the toilet in the bottom of the tank. I had to remove the valve to get it out. It would float up to the valve and block the outlet. I found it by chance when I was looking down the toilet with a flash light and it floated by.
