Those inaccurate tank indicators

 

Filling outside freshwater tank #1

A couple of days ago I ran the Onan generator for its monthly exercise.  I also added 16 ounces of Seaform to the Chevy gas tank, which was about 1/2 full.  At that time all of the tanks were empty except freshwater tank #1. That tank read 1/3 full. All the other tank level indicators read empty.  Each year as summer arrives, I am aware of complaints on social media.  One of these is about those inaccurate tank sensors.  One individual over at Fakebook commented to a post asking for help "Those indicators never work.  Do yourself a favor and just tape over them."

That's a defeatist attitude and it is not necessarily accurate.  We live in a travel trailer, a 5th wheel and the Roadtrek for most of the year (about 45-50 weeks).  All of the tank level indicators work in all of those RVs and we use the fresh tanks, gray tanks and black tanks.  However, to keep them working there are a few things one must do.

One issue is soap scum.  We've experienced issues in the gray tank of the 5th wheel, in which we live for up to 6-months a year.  I could clean that tank, but I simply don't bother.  My primary reason is the tank is so large, we simply dump it every few days and don't think about it.

The Roadtrek is another thing altogether, because the tanks are small.  

2013 210P Approximate Capacities:

• Fresh water, total 36 gallons (6-gallon hot water, approx. 15 gallons outside tank #1, 15 gallons inside tank #2).
• Gray tank 23 gallons.
• Black tank 10 gallons.

Because of the small gray and black tank capacities, we pay attention to the LED indicators.

How to keep the gray and black tank level indicators working

Our Roadtrek is about 9 years old, we camp a lot and have actually lived in it for up to 100+ continuous days. All of the tank indicators work as designed and we have never had an issue with the macerator.  We use the commode, the sinks and the outside shower.  We winterize if we are trekking below 20F or expect outside temperatures to be below 32F for extended periods of time.

Now, a cynic might say that our experience is not typical, and we simply experience "good luck".  That may be true.  It might be useful to ask, "How do we keep the indicators and macerator working?" 

1. Nothing goes into the toilet except for human bodily waste and Scott septic safe toilet paper.
2. Nothing goes into the sinks or shower drain except water and soap residue.  We don't let hair accumulate in the drains. 
3. We dump the black tank every couple of days, and we always add a gallon or so of fresh water to the emptied tank.
4. We dump the gray tank after the black to flush the macerator hose with water devoid of solids.
5. After using the macerator, I lift the hose and "walk it" toward the dump, assuring all liquid drains from the hose.  I installed a very flexible Thetford "slinky" in 2014 and we have used it ever since. 
6. Each year I flush the gray and black tanks with a generous amount of fresh water. 
7. We use Dawn dishwashing liquid.
8. I once used "Happy Camper Extreme Holding Tank Cleaner".  I've got a link to the posts about that.  What we discovered was soap scum was interfering with the gray tank sensors.  We switched to Dawn and that problem went away. More about this later in this post.

Click for Links to Tank Level Sensor Posts

Cleaning and sanitizing the freshwater tanks

A couple of days ago I drained the freshwater tanks after an extended trek.  I do this so I can sanitize the freshwater tank system.  We've been in campgrounds with freshwater I considered suitable for cleaning, but not for drinking.   After one such experience and in high summer temperatures I discovered beer brewing in my outside tank #1.  Apparently, there was algae or bacteria in that water.

My procedure is straightforward. I completely drain the freshwater system.  Then I refill the freshwater tanks and drain again. That approach flushes anything in the tanks. Then I add a bleach mixture to the freshwater tanks. Here is an outline of the steps I use on our 210P:

1. Drain the hot water heater.  I usually don't sanitize the heater and so after emptying I use the bypass valves to isolate the heater, so no water enters or leaves it during the sanitizing.
2. Park the Roadtrek level, or with the front slightly lower than the rear.
3. Open the exterior freshwater tank low point drain valve.
4. Open the interior tank drain valve, which is inside the water pump cabinet.
5. Allow the entire freshwater system to drain completely and then close the exterior freshwater low point drain valve. 
6. Close the interior tank drain valve. 
7. Fill both the interior and exterior freshwater tanks once again with fresh water.  Then drain completely.  This step flushes anything in the tanks. See steps 8, 9, 10.
8. Open the exterior freshwater tank low point drain valve.
9. Open the interior tank drain valve, which is inside the water pump cabinet.
10. Allow the entire freshwater system to drain completely and then close the exterior freshwater low point drain valve. 
11. Close the interior tank drain valve. 
12. Mix 1/2 cup of bleach with fresh water and introduce it into the outside gravity fill of tank #2 (the interior freshwater tank).  1/2 cup is sufficient for about 25 gallons of fresh water.
13. Add about 10 gallons (or more, or less) to the interior freshwater tank #2.
14. Open the interior tank drain valve, which is inside the water pump cabinet. This will allow the water in that tank to flow via gravity toward exterior tank #1.
15. Allow freshwater tank #2 to empty and then close the interior tank drain valve. This will isolate the two freshwater tanks.
16. Add sufficient water to freshwater tank #1 (the exterior tank) to fill it.  
17. That's it.  Running the water pump and opening various taps will move this bleach-water blend throughout the freshwater lines.  During the summer I usually only use the exterior freshwater tank, so I close the isolator valve that drains interior freshwater tank #1.

Cleaning and sanitizing the black and gray water tanks

I did once used a chemical treatment on the gray tank.  That was in 2016 after living the Roadrek for about 100+ days.  I've included a blog link about this.  I used "Happy Camper Extreme Holding Tank Cleaner".  This is a caustic chemical which can result in burns or injury or damage. Follow all manufacturer's directions and safety precautions.  There are warnings on the product labels, and one shouldn't allow the chemical touch the skin or eyes.  I use extreme caution. 

We have since changed our procedures

We rinse the gray, black and freshwater tanks annually and then sanitize the freshwater tanks.  We only use Dawn dishwashing liquid and Dove for sensitive skin bar soap.  We have never used the interior shower, preferring those at campgrounds.  Instead, we take sponge baths.  No shampoo or residue gets into the gray tanks.  We winterize once each year, and that includes the P-Traps.  Once warm weather arrives, we fill the P-Traps with fresh water.  We keep the floor drain screw-in strainers closed at all times.  If any debris collects in the aisle or the bath, we vacuum it out before opening these strainers. 

Here's some blog posts about the issues we once had with the tank indicator's and how we resolved them.

http://roadtrek210.blogspot.com/2016/04/those-inaccurate-black-and-gray-tank.html

Accompanying Youtube Video:  

https://youtu.be/BXwLOIVVNRo

(c) N. Retzke 2022

Those Inaccurate Black and Gray Tank Sensors - Updated

Updated May 23, 2016

Both gray and black water tank levels now function reliably. The photo above was taken yesterday, after the cleaning of the gray tank. It now registers "empty" when empty, and with about four gallons in it shows 1/3 full.

After driving 250 miles with about 6 gallons of treated water in the gray tank I dumped it into a bucket.  I then added four gallons of fresh water and dumped the tank. I did so one more time until the macerator discharge was clear. I pumped the tank into a bucket so I could observe what came out of the tank.

Here is what came out of the gray tank after sloshing with the water/chemical mixture:

Before adding the chemical treatment, I dumped the tank, then added about eight gallons of fresh water and dumped it again. The water that came out was clear. I then put about 6 gallons of chemically treated water into the gray tank and let it sit for a couple of days, while driving about 250 miles.

The bucket shows what was pumped out after treating.

We've stopped using a popular dishwashing liquid and have switched to Dawn. G was resistant but she now sees the consequences.

DISCLAIMER - This information is provided as my amateur observations. It is not an endorsement or a recommendation for any product or method. Do your own research and follow all manufacturer's instructions for any product or procedure you may decide to use. I bear no responsibility for results or the lack of them.




Original Post May 18, 2016

Those point level gages on RVs are frequently inaccurate. For example, the gray tank in the photo is empty but the indicator displays two-thirds full. At the same time the black tank indicator was also non-responsive.

Our tank level gages have steadily worsened and after several months in an area with hard water they no longer respond to tank level changes. We dump, rinse the tanks and fill and the indicators never change.

We've read about a variety of treatments including rinsing with a solution of Dawn dishwashing liquid, using Borax, and even dumping ice cubes into the black tank via the toilet and letting it swish around for a while. I was convinced that hard water had fouled the sensors, leaving calcium deposits. So I tried several gallons of a 6% solution of vinegar. None of the things we tried worked.

I was told over at Facebook to give up. I decided more drastic measures were necessary.

I decided to try a chemical for the purpose. I followed the manufacturer's directions except I used a weaker solution. After putting about three gallons of a water/chemical mix into the empty black tank we continued on our trek and drove all day. About 12 hours later I dumped the tank, filled it with clear water and dumped it again.

After cleaning and dumping here is what the [black] tank indicator displays for an empty tank:

To test the tank sensor I again rinsed and dumped, It showed empt. I then poured two buckets of water into the toilet. That's about 3 to 4 gallons of water. The tank level indicator then showed two LEDs, or about one-third full.

I then pumped the contents of the black tank into a bucket. After dumping two buckets the tank was empty.

I then rechecked the tank level sensor and it again showed one LED which is an empty tank. Apparently the chemical cleaning had worked.

I'll next do the grey tank, but I'll have to wait until we have an all day trek so I can again let the mixture slosh around while we drive.

What Did I Use?
Before reading on I suggest you read the following disclaimer. I am neither promoting or recommending any treatment or product. I am reporting my personal experience. Yours might be different. USE AT YOUR OWN RISK.

DISCLAIMER
All content in this blog is provided for information purposes only. The information contained here should not be consider “expert” and not taken as specific advice. The author makes no representations as to the accuracy, completeness, or reliability of the information on this site or that is found by following any link. The information contained here and in the links may become outdated.The author will not be held liable for any errors or omissions in this information. The author will not be held liable for any losses, injuries, or damages from the use or display of this information.

The product I used is "Happy Camper Extreme Holding Tank Cleaner." Note: Follow the manufacturer's directions.