As many before me have had holding tank sensor issues, I know that faulty readings are nothing new. I've looked into the See Level and other type of "through the tank" monitor strips, but they require getting access to the side of the tank. My tanks in my camper would require me to drop the belly pan and gain access from there and I'm not willing to do that just to get accurate monitors. I have fairly easy access to the top of my tanks and wanted to know if any vendor offers a through the top monitor setup. I would be less worried about drilling a new hole in the top of the tank, vs the side so the fact that I'd have to drill into the tank isn't an issue to me. Just wondering if anyone has seen a setup with top mounted monitor/float assembly.Thanks for any leads.

Nope....side mount onlyToilet burps..time to dumpShower/sink starts to drain slower....time to dumpWater pump goes ''burrrrrrrrr'...should have added more waterI haven't looked at my level gauge monitor panel in almost 7 yrs.

To the OP, the only sensors that really work are the See Level external type. You don't have to drop the entire under belly, you can cut a large access hole in the plastic and seal it up with Gorilla Tape, or just live with inaccurate sensors live I have for the last 10 years on 2 trailers.

Cutting a 3 sided access panel is the best way to access the tanks. Fwiw, the gauges on my tanks are located near the valves. I currently open an access panel a while back to service my valves and can always reopen it if needed to service valves or gauges by removing gorilla tape. The tape holds well. Btw - I also don't care if my gauges are accurate. I know when the tanks need dumping or filling based on use, sounds, etc.

Add 15 gals of water and 3 lbs of rock salt to the black tank before your next trip. If that doesn't clean up your sensors, they are really messed up.

last year in the high heat I started to get false reading of 3/4 full. Flushed tank out with the Hydro flow fitting on the dump hose. It is a right angle with a hose water hose attachment. Then added the enzyme solution for the black water. Filled it with a third tank of water and drove 5 hours to the next campground and dumped. No more problem. The sensors get coated and give the false reading. Try this before you drill holes or try to remove sensors.

Holding tank monitor sensor question | Good Sam Community

15 Replies

time2roll
Nomad
Dec 10, 2014
Can you add a flush system from the top?

I added a no fuss flush with a custom spray pattern to hit the sensors and the oem system is working perfect. Although the bottom two indicators are far less important than the top two.
64thunderbolt
Explorer II
Dec 10, 2014
Ron3rd wrote:
CAJW wrote:
I'll try the rock salt and/or ice cubes method, but oddly enough, the issue is with the fresh and gray water monitors. AFAIK, the black tank monitor is working properly. Also, as luck would have it, the only tank monitor wiring that is accessible, without removing the belly panel or cutting access panels, is the black tank. Unit is only a year old so I'm a bit surprised that the fresh water especially is acting up already. We've got very good water (low in minerals, almost soft) where I live and have only filled the tank once from an alternate source which was months before the monitor went kaput.

I would not add rock salt to any tank. Highly corrosive and can damage the retaining bolts on the dump valves. Rock salt is the last thing I would add to a holding tank.

If water gets to the bolts the orings are leaking.
wa8yxm
Explorer III
Dec 09, 2014
I have a design Id like to build for a top mount but have not yet gotten round to it,, If you can access the top you may be able to install See Level from there, (You need to be able to reach down beside the tanks)

What I do not know is why they do not plug a flat plate under the tank and a load cell on it, then they can very simply weigh the tank with the load cell, as it fills, it gets.. Heavier.
Oldme
Explorer
Dec 09, 2014
The insides of both Gray and Black will form a "scum"
on the wall that will conduct the electrical current
from the sensors. Break the scum and you will stop
the false reading.

I have found that along with adding a small bottle
of Dawn Liquid after every dump, add either a
water softener or a dish-washing machine cleaner
like Cascade that has "sheeting action".

The water softener and the sheeting action of the
dish washer detergent like Cascade will cause
the "scum" to run off and not dry / stay on the walls
of the tank.
D1wkrueger
Explorer
Dec 09, 2014
You can get a JAKmeter.com that installs on your pump and always know what you have for fresh water. No need to access the tank, just the water pump.
coolbreeze01
Explorer
Jun 05, 2014
CAJW wrote:
I'll try the rock salt and/or ice cubes method, but oddly enough, the issue is with the fresh and gray water monitors. AFAIK, the black tank monitor is working properly. Also, as luck would have it, the only tank monitor wiring that is accessible, without removing the belly panel or cutting access panels, is the black tank. Unit is only a year old so I'm a bit surprised that the fresh water especially is acting up already. We've got very good water (low in minerals, almost soft) where I live and have only filled the tank once from an alternate source which was months before the monitor went kaput.

The salt was recommended for sensor cleaning in my Komfort owner's manual. Let us know how it works.
BoonHauler
Explorer
Jun 05, 2014
CAJW wrote:
As many before me have had holding tank sensor issues, I know that faulty readings are nothing new. I've looked into the See Level and other type of "through the tank" monitor strips, but they require getting access to the side of the tank. My tanks in my camper would require me to drop the belly pan and gain access from there and I'm not willing to do that just to get accurate monitors. I have fairly easy access to the top of my tanks and wanted to know if any vendor offers a through the top monitor setup. I would be less worried about drilling a new hole in the top of the tank, vs the side so the fact that I'd have to drill into the tank isn't an issue to me. Just wondering if anyone has seen a setup with top mounted monitor/float assembly.
Thanks for any leads.

See Level and Tech Edge both offer a top mounted tank sensor. Call them and ask about it. It's custom made for the depth of your tank. It's takes a 1 inch female pipe thread tank fitting to mount it.
Ron3rd
Explorer III
Jun 05, 2014
CAJW wrote:
I'll try the rock salt and/or ice cubes method, but oddly enough, the issue is with the fresh and gray water monitors. AFAIK, the black tank monitor is working properly. Also, as luck would have it, the only tank monitor wiring that is accessible, without removing the belly panel or cutting access panels, is the black tank. Unit is only a year old so I'm a bit surprised that the fresh water especially is acting up already. We've got very good water (low in minerals, almost soft) where I live and have only filled the tank once from an alternate source which was months before the monitor went kaput.

I would not add rock salt to any tank. Highly corrosive and can damage the retaining bolts on the dump valves. Rock salt is the last thing I would add to a holding tank.
CAJW
Explorer
Jun 05, 2014
I'll try the rock salt and/or ice cubes method, but oddly enough, the issue is with the fresh and gray water monitors. AFAIK, the black tank monitor is working properly. Also, as luck would have it, the only tank monitor wiring that is accessible, without removing the belly panel or cutting access panels, is the black tank. Unit is only a year old so I'm a bit surprised that the fresh water especially is acting up already. We've got very good water (low in minerals, almost soft) where I live and have only filled the tank once from an alternate source which was months before the monitor went kaput.
Lantley
Nomad
Jun 05, 2014
Old-Biscuit wrote:
Nope....side mount only

Toilet burps..time to dump
Shower/sink starts to drain slower....time to dump
Water pump goes ''burrrrrrrrr'...should have added more water

I haven't looked at my level gauge monitor panel in almost 7 yrs.

Exactly My sensors work just like yours!