Gray water sensers

[brucebollert]

I have a 2016 FR sunseeker MBS. Does anyone know how the gray water sensers work? Are they inside the tank or outside? Can they be replaced? Mine haven’t worked since 1st year.

[TitanMike]

Originally Posted by brucebollert

I have a 2016 FR sunseeker MBS. Does anyone know how the gray water sensers work? Are they inside the tank or outside? Can they be replaced? Mine haven’t worked since 1st year.

The sensors are essentially just machine screws with the heads inside the tank and nuts outside that compress a rubber grommet as well as provide a means to connect wires.

Nothing mechanical or electronic, just a conductor. When liquid completes the circuit from the lowest conductor (the common) to the next one up it triggers the first level indicator. Repeats for each one up the side of the tank.

Because these "conductors" are close to the tank wall it's easy for any crud that builds up on the tank wall to short from conductor to conductor and create false readings.

They can be replaced but if you are doing so I'd recommend replacing with the Valterra "Horst Miracle Probes" which have a different design. The probe extends the contact point significantly away from the tank wall and short circuiting is avoided.

Same type of probes for the black tank are made but also include a half round tube that shields the top of the probe from any solids from fouling and shorting the probe itself.

Available on Amazon.

[OLEJOE]

Just went through the same thing on our 25KBH East2West. Started acting up while we were on a long trip. Here’s how I cleared or cleaned mine. I tried tons of water flushing the tank but it didn’t work. Take 20+ ounces of Dawn dish washing liquid and mix it with a gallon of water. Pour it down the kitchen drain. Next fill your gray tank with hot water through the kitchen sink. I have a tankless water heater in my house so it was easy and used it through a hose. Let it sit overnight and you won’t believe what will come out of it when you drain it the next day. Refilled ours and rock the trailer around and dumped that. All sensors working properly now. The next time we camp and have full hookups I’m going to leave the gray water valve open. Hope this helps. It fixed ours.

[SeaDog]

[ All sensors working properly now. The next time we camp and have full hookups I’m going to leave the gray water valve open. Hope this helps. It fixed ours.[/QUOTE]

I would advise against this as you will allow the sewer gas from the campground to flow back into your rig. To the OP try using the geo method to keep your tanks clean. scum builds on the sidewalls causing the false readings.

[OLEJOE]

Forming a small trap in the discharge line prevents sewer gas from backing up in the trailer system.

[brucebollert]

Thanks all for your suggestions. I have tried the GEO method once, I think I will try again before looking at sensor screws. Try the easy stuff first.