How accurate are the holding tank gauges on your RV?


Are your RV’s holding tank gauges reliable? Do they accurately show the level of your  holding tanks — black, gray and fresh water — and LP gas?

Or are they never or seldom correct? Curious minds would very much like to know.

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Sink Jaxon
6 months ago

My BLK tank always reads full even tho I’ve flushed it out at almost every dump. I bought it new and it worked fine for maybe the first two months. It’s been 1.5 years now. The GRY and FRSH tank registers work fine. They are the push and hold for the red light to come on, type.

Range Rider
5 months ago
Reply to  Sink Jaxon

Order you some Happy Camper additive. It will most likely solve your problem. I get mine from Amazon.

6 months ago

They’re all useless for the most part. Very frustrating that the gray tanks do not work properly. They haven’t on any of our four travel trailers.

Stephen Willey
10 months ago

I checked “very accurate” because I replaced the stock gauge with an electronic tank monitor that uses foil tape on outside of the tanks to sense levels. Bit of work, because the new system needed one more wire from each tank than the original. But it works great. HEY! this hgas been an issue for decades. Why don’t manufacturers update and quit using those cheaper pin through the tank gauges that always foul up?

Colin Grant
10 months ago

My black tank gauge is useless. I`m lucky though if I shine a flashlight down the toilet with the slide open the tank is directly visible below. My grey tank is reasonably accurate but if you fill to the max it will come out on the shower floor which isn`t a problem. Fresh and propane are good. This is on a Pleasure Way Sprinter class B, an older model.

10 months ago

They worked fine for three seasons and that was it. Even had the tanks power-washed and replaced the sensors. Tried almost every tip I read here on RVTravel. Bought cleaners from Amazon with no success. So I just dump them every few days.

Bluebird Bob
10 months ago

We have had a MicroPulse indicator with probes. Have had it now for over 10 years and VERY accurate. Love it!

10 months ago

Ours have not worked from day 1. When we did our inspection I noticed gray tank #1 was reading 3/4 full, gray tank #2 was 1/2 full and the black tank full. The dealer knew they did not work and stated there was nothing they could do about it. According to them that was worked into the price of our brand new 5th wheel. That took them 3 months to get. I never tried getting Grand Designs to warranty it, because I don’t want the dealer to take a few months trying to fix something that they know doesn’t work and then sell it that way anyway.

Sink Jaxon
6 months ago
Reply to  M.J.

Just don’t seem right , does it…

10 months ago

I think one of the choices should have been accurate enough. Usually if it reads 1/2 a tank it gets emptied.

Lynn Benzel
10 months ago

I think the gauges suck. Never tried to correct. Why put out the money. Factory should make it right.

10 months ago

My gauges work fine. I do flush and empty tanks frequently and never but toilet paper in black tank. The outside propane tank gauge is accurate but the gauge inside RV is not accurate. This Class C is my 4 th RV been RVing about 6 months a year for last ten years and RV ing since 1995. I’m 71.

Jim Thompson
10 months ago
Reply to  Brian

So how do you wipe???

10 months ago

For anyone who is interested, here is the link.

10 months ago

My readings on my tanks are accurate because I installed SeeLevel tank sensors. About $100. Worth the price.

Vanessa Simmons
10 months ago

Being solo I empty the black tank every other week and usually the bathroom gray tank at the same time to rinse out the hose. The gauges haven’t been accurate since I bought it two years ago. The kitchen gray tank I empty as needed…sometimes when the water backs up in the sink! 😉

Carl M
10 months ago

My Tech Edge sensors are working well after six months. Install involves a lot of crawling around under the trailer to install foil tape on each tank and run a 3-conductor cable to each tank. The system needs to be properly calibrated after install. My tanks are shallow, so being out of level gives an incorrect reading.

Daniel Pankiewicz
10 months ago

No matter how I empty, the chemical used, multiple clean water flushes, gauges still read full . Thus useless in my opinion.

robert garder
10 months ago

The Seelevel system is available from I have had mine installed for 4 years and am very satisfied with the system. Installation is easy as you can utilize the existing wires. The hardest part is gaining access to the tanks to attach the sensing strips.
I would buy this system again.

10 months ago

Mine are “somewhat accurate AND generally reliable.” Probably the case for many, but can’t choose it the way the choices are written.

Rocky J
10 months ago

I read a comment several years ago that one person recommended putting Calgon in black water ….this will prevent any materials sticking to the sensors.
Note..we still use soap and water to clean out the tanks!!

Gene Bjerke
10 months ago

Our monitor levels (lights) are reasonably accurate for everything but the black tank, which is useless. On longer trips, I have begun to use a system based on the fact that the total capacity of my sewage tanks is pretty much equal to the capacity of my fresh water tank. This is done to keep the rig balanced as the water is transferred from the fresh tank to the waste tanks (some of it via the humans aboard). Thus when the fresh tank is getting low, it is time to dump the holding tanks. I dump and reload at about the same time — but not at the same place. Seems to work so far.

Karen K Willis
10 months ago
Reply to  Gene Bjerke


10 months ago

I have the old fashioned electrical contacts drilled through the tank walls but the installer did not place them accurately. So, starting with an empty tank add water by the bucketful (most buckets are calibrated) until the gauge flicks over to 1/3 full and note the number of gallons added. Continue until you get to 2/3 full, then again till it reads Full. Post a little chart by the gauge and never again be concerned with a reading that’s much higher than you expected.