Best Way to Clean Holding Tank Probes? - Resolved

gratcho

New member
Joined
Sep 6, 2008
Messages
76
Our Sealand Tank Watch 4 sensor is starting to give faulty readings saying the tank is low when empty, and not clicking up to mid when it really is. We have a plastic tank that I can access and visually check the level.

I'm betting the probes are gunked up. I plan to check it out (after opening every door and hatch on out boat, and getting the family out of the cabin)

What's the best product and technique to throughly clean the probes?

Is it better just to replace them?

Thanks as always for the great advice!

Thanks!!
 

pdecat

Well-known member
Member
Joined
Jan 1, 2000
Messages
11,589
No need to open the tank. Just add some water to half full and take the boat for a run sloshing it around as much as possible. using the boat a lot will prevent the problem. IMO there is no complete fix except keeping them wet with frequent use.
 

Shake n Bake

Member
Joined
Mar 8, 2005
Messages
370
Make sure the electrical connections are secure, too. Sometimes a weak connection makes a probe not read properly.
 

gratcho

New member
Joined
Sep 6, 2008
Messages
76
Thanks for the responses - we use the tank frequently, pumping out at least once a week. We've had her for a year and half, the empty reading rarely worked, I'll try pumping out before going out, filling it up with fresh water and see how it goes. I read on another board that urine crystals can build up which cause the sensor switch to stop moving.
 

pdecat

Well-known member
Member
Joined
Jan 1, 2000
Messages
11,589
Urine crystals or dried $hit or techno babble. just keep it wet and the problems will disappear.
 

rawidman

New member
Joined
Feb 5, 2007
Messages
3,177
If you post your question in the "Marine Sanitation, Plumbing and the like". section, you may get some additional advice.
 

Flatstick

New member
Joined
Oct 9, 2007
Messages
14
I've had the same problem with our motorhome. They make a tank/sensor cleaner for motorhomes. We would just dump 20 lbs of Ice in and go for a drive, worked great.
 

whiskywizard

New member
exMember
Joined
Jan 4, 2006
Messages
45
There are no "probes" on a Sealand Tank Watch 4. It uses 3 floats that close/open microswitches. If you never get an empty indication you have 1 of 2 likely problems; the lowest float has some debris stuck under it preventing it from dropping fully, or the lowest float's stalk has been adjusted too long and is always in liquid even after you pump out. (you never empty that tank 100% - there's always some left)
Either way, it's time to snap on the gloves...
 

MIke F

New member
Member
Joined
Mar 2, 2000
Messages
492
You can switch to a capacaitive sensor which uses 2 metal foil strips on the outside of the tank. as the tank fills the dielectric constant sensed by the foils increases increasing the capacitance. The capacitance is read by the electronics determining the degree of fill of the tank. Since the foil electrodes are external to the tank there is never a problem.
 

gratcho

New member
Joined
Sep 6, 2008
Messages
76
Thanks all for the advice - I'm happy to report my lovely bride did such a great job keeping our head treated, that there was little odor when I gathered my courage and got to work on the sensors. There was very old dried waste on the probes, I soaked a rag with Sealand head cleaner and wrapped the float with it. It loosened up the stuff in about a minute and the three floats and tubes look great.

I have an idea for the future - I'm thinking about adding a lawn sprinkler head inside the tank opposite the pumpout hose. I'm thinking if I hooked it up to a water source and spray fresh water as we're pumping out. Maybe that would make sure I rinse out the sludge.
 

Shadowcruzr

New member
exMember
Joined
Jan 1, 2000
Messages
1,621
My camper has a water hookup to flush the tank. It sprays all around the tank to clean off the probes and to clean out the tank. I recommend it for all tanks.
 

CPSS

New member
exMember
Joined
Mar 20, 2004
Messages
345
tornado-tank-rinser-parts-1-330x190.jpg


Tornado holding tank rinser kit
 

gratcho

New member
Joined
Sep 6, 2008
Messages
76
That's exactly what I was looking at - I was worried it might blast the sealand tank sensor too hard, but looks like it's ok huh?

I was thinking of mounting the source point for water near the pumpout point, so I can hook up a hose and watch for clear water being pulled out. Where did you gents put the inlet?
 

Planeguy

Member
Member
Joined
Jan 1, 2000
Messages
395
I used the Tornado in the tank of my Silverton 34C. It seemed to work a few times and then would not spin around anymore. Now I have a Silverton 41C with a Sea Land Tankwatch III installed. I can pump out the holding tank and the green (EMPTY) light will be the only light illuminated on the panel. After one or two uses the amber (MID) light will illuminate followed shortly by the red (FULL) light. My annunciators will illuminate when they should be off. I use chemicals that say they clean probes but no good results. Going to try pulling out the sensors and cleaning them before winter haul out.
 

Planeguy

Member
Member
Joined
Jan 1, 2000
Messages
395
UPDATE.....Went to remove the vent tubing from the sensor panel on the top of the holding tank and it was full of "water". I had pumped out last Sunday afternoon and the head had not been used all week but somehow the tank was actually full. This new to me boat has a macerator and the thru hull valve was in the open position which is a no no on the Great Lakes. It seems the water was seeping backwards thru the macerator and back filling my holding tank. Valve closed problem solved.
 

teatalkone

New member
Joined
May 29, 2021
Messages
1
Empty your tanks. The first step to thoroughly cleaning your RV tanks is, of course, to drain them, even if they're not entirely full. ... Refill the tanks a third of the way with fresh water and add soap. Drain your tanks and re-check your sensors. shareit vidmate app
 
Top