Community Forums

leegrisham · 10-13-2020, 10:37 AM

2017 Winnebago Vista 35F

Since nothing we have tried will get the tank sensors to read accurately, I was considering removing the manifold so I could reach into the gray tank and clean the sensor by hand. Since they are electrical, is there a risk of shock?

Is there a way to test them via voltmeter?

**Lt Dan** · 10-13-2020, 10:45 AM

Unless Winnebago has made a major change, the sensors are on the outside of the tank and don't penetrate to the inside. They read the difference in density through the plastic. Even the ones on our '06 Itasca were that type. Usually if they are reading more than is true either there is a crud buildup on the inside walls or the sensors are misplaced on the tank walls. In the case of our Itasca there was a 1/16" thick buildup of grease and gunk coating the wall. It took several applications of Dawn detergent and the installation of a Turbo sprayer in the tank to finally get it cleared up.

Bsipe01 · 10-13-2020, 10:49 AM

It depends on the type of sensor. Start by determining what kind of sensor you're working with, otherwise you can't know the best approach for cleaning.

Our Phaeton has sensors on the outside of the tank, so you don't actually clean the sensor, you clean the wall of the tank. I was able to clean the black tank wall at the sensor by putting the pressure washer wand down the drop pipe from our 1/2 bath toilet. Have one of those nifty angle adapters so it wasn't too hard to get the pressure washer stream directed against the wall of the tank to blast it clean. Seems to have helped. The gray water tank has no real access, so just some tank cleaner in a half tank before a travel day.

Avoid using bar soap, it makes a curd that accumulates. Soap is, after all rendered fat.

Dav L · 10-13-2020, 10:59 AM

power wash the interior of the tank. Thru both the toilet exit (wrap a towel around the hose to prevent blowback) and also from the bottom of the tank exit. Use a "jetter" nozzle. I can't imagine any debris would not get cleaned up.

MSHappyCampers · 10-13-2020, 11:03 AM

Quote:

Originally Posted by Dav L

power wash the interior of the tank. Thru both the toilet exit (wrap a towel around the hose to prevent blowback) and also from the bottom of the tank exit. Use a "jetter" nozzle. I can't imagine any debris would not get cleaned up.

X2!

FIRE UP · 10-13-2020, 09:14 PM

Quote:

Originally Posted by Lt Dan

Unless Winnebago has made a major change, the sensors are on the outside of the tank and don't penetrate to the inside. They read the difference in density through the plastic. Even the ones on our '06 Itasca were that type. Usually if they are reading more than is true either there is a crud buildup on the inside walls or the sensors are misplaced on the tank walls. In the case of our Itasca there was a 1/16" thick buildup of grease and gunk coating the wall. It took several applications of Dawn detergent and the installation of a Turbo sprayer in the tank to finally get it cleared up.

Yiiiiip,
Our coach, an 04 Itasca Horizon 36GD with the CAT C-7 330HP, also has what I call *radar* type sensors. They read THROUGH the tank walls. Mine had been working flawlessly for 6-7 year or so then, all of a sudden I got some odd readings. Well, long story short, one of the sensors that was attached to the upper part of the tank, had fallen and was reading BELOW the sensor it used to be above. Talk about some odd readings.

Anyway, found the problem, fished out the fallen sensor, re-attached it to where it was originally and, all is well. But, yes, I too am assuming that Winne still uses those types of sensors in todays built coaches.
Scott

Ray,IN · 10-13-2020, 09:22 PM

Our MH has the old style sensors that are held into the tank wall with a nut. The end of the sensors are inside the tank. Yes Winnebago did make a change.

leegrisham · 10-14-2020, 08:46 AM

Yes my sensors are on the outside too. Guess I thought there was more to it. This is specifically the grey tank. I have a wand for the black tanks and that is very effective. The grey tank has no access other than the manifold. I have tried Dawn before with imperfect results. I go from full to 1/3rd instead of zero but not that good lately. I guess I can try that again on my way to Pahrump. What have I got to lose!

Appreciate the responses.

sneaky · 10-18-2020, 07:34 AM

Empty the black tank, dump in either 2 small bags of ice cubes or one 25 lb. bag thru the toilet and go for an aggressive ride with lots or cornering and braking, after they melt dump the tank. Being in NY I have to do this in warm weather so the ice will melt fairly quick. Have done this in several motorhomes and has worked well. I have tried the sensor cleaners and have not had much luck with them.

Ray,IN · 10-18-2020, 09:23 PM

Quote:

Originally Posted by sneaky

Empty the black tank, dump in either 2 small bags of ice cubes or one 25 lb. bag thru the toilet and go for an aggressive ride with lots or cornering and braking, after they melt dump the tank. Being in NY I have to do this in warm weather so the ice will melt fairly quick. Have done this in several motorhomes and has worked well. I have tried the sensor cleaners and have not had much luck with them.

There is a

utube video

of a man constructing a clear plastic tank then running test of ice cubes to clean the tank.

Since ice floats it cannot contact any sensors below the ice level or above liquid level. I am glad it cleaned yours.

sneaky · 10-19-2020, 06:42 AM

Yeah... uTube is full of videos, most are BS. I did mention "empty the tank" FIRST. So nothing inside, ice will be sloshing around and eventually melting. I have had this work on maybe 3 motorhomes I've had, it's cheap and worth a try. After owning 43 motorhomes I have tried just about everything.

GypsyR · 10-19-2020, 12:39 PM

"43"? Good lord. Hey, start a new thread about who has owned the largest number of campers.

NRR · 10-19-2020, 03:16 PM

Just ignore the readings. They are almost never right. It only reading I trust is the fresh water tank reading. I use that tank for all my water. So it is always clean. Watching that tank tells me how much water has been used. I can then estimate if the gray tank reading is possibly right. There is also the water in the shower indicator I understand. Never had that happen.

The black tank I can look down the hole and see it with the pump turned off.

I always put Dawn in both tanks. Along with Calgon if I can find it around here. It is part of the “geo method”. Not a fool proof method. But it helps.

EdInArk · 10-19-2020, 03:26 PM

I've cleaned my black tank a couple of times now with Commando. I just followed instructions, and it worked great! After emptying the tank, the gauges read empty just as they should. It was wonderful.

Then, before sundown the next day of camping the sensors were fouled again.

I've given up. ;(

Seriously, as easily as they're fouled I sure wouldn't go to any great extreme to clean them. But maybe that's just me.