I have a small holding tank on my Grady Freedom 285. The level display on the macerator panel (Jabsco) constantly flashes full when I know the holding tank is empty. Is there a way to recalibrate the sensor or, if necessary, replace the sensor? Thanks.
Holding Tank Level Reset
- Thread starter JLR
- Start date
Assuming you can get to the tank, remove the connection for the sensor wire and see if the display changes. If so, the sensor is bad or just stuck. The sensor is replaceable but how depends on the model of the holding tank. Sometimes a stuck sensor can be unstuck but that can be a messy job. Try tapping the top of the sensor if you can get to it easily enough. That may free up a stuck sensor ( for a while at least)
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I tried to remove my sensor but it wouldn't budge. Looks like contact cement used as sealant. Has a 8-sided head on could not find a socket to fit. Gave up. Reads empty and full.
I would fill holding tank with water, run boar or trailer around and dump it a few times. May shake it loose. I take overboard hose off and pump into 5-gallon bucket and dump in the house. It cleans up quickly and not that dirty a job.
I would fill holding tank with water, run boar or trailer around and dump it a few times. May shake it loose. I take overboard hose off and pump into 5-gallon bucket and dump in the house. It cleans up quickly and not that dirty a job.
Does your display normally change colors depending on the tank level?
If so, you may have a Jabsco MSD III model tank and that doesn't use the typical float sender. The control panel looks at 4 signals from sensors in the tank tat are mounted at different levels.
If you have that type, your display changes colors for empty, half full, 3/4 full and flashing red, full.
I don't know exactly how the electronics work so if that sounds like your system, you might want to contact XYLEM (parent of Jabsco) for help.
If so, you may have a Jabsco MSD III model tank and that doesn't use the typical float sender. The control panel looks at 4 signals from sensors in the tank tat are mounted at different levels.
If you have that type, your display changes colors for empty, half full, 3/4 full and flashing red, full.
I don't know exactly how the electronics work so if that sounds like your system, you might want to contact XYLEM (parent of Jabsco) for help.
No joy. I cannot really reach the tank. And, the only way to get the flashing to stop is to shut off the main battery switches. I can't believe there is no breaker for the head. What am I missing?
I looked at a 2015 user manual and it seems that the toilet is powered through a fuse in the fuse block. The holding tank in that 2015 is under the deck just behind the walk thru windshield. There has to b either a deck panel that can be removed or a panel in the head compartment or in the starboard helm compartment.
Turns out I can reach the top of the tank to unscrew the evacuation port. I have confirmed the tank is empty but the display is still flashing full. It is the Jabsco MSDIII unit. I cannot see any top mounted level sensor. Since I can get into the evacuation port (just barely) is there something I might snake inside to get to the float or whatever activates the level sensor. From looking at pictures, it looks like it might be some side mounted plate of some sort. Also, as for recalibrating the sensor, I press the "secret button" below the Jabsco name but get no tactile feedback that there really is a button there. Could the display be the problem?
There is no top mounted sensor. That model uses three separate ' sensors' on the side of the tank each connected to a wire that eventually ends up at the display/control panel.
I am not sure how to troubleshoot but I would check the connectors for the wires. I suppose the tank might be coated on the inside with gunk that is making the sensor think the level is high. It's more likely I think that the control module is bad but I wouldn't rush to replace it without better diagnostics.
Perhaps Xylem has some troubleshooting advice. You might try calling them. I will take a quick look for anything helpful
I am not sure how to troubleshoot but I would check the connectors for the wires. I suppose the tank might be coated on the inside with gunk that is making the sensor think the level is high. It's more likely I think that the control module is bad but I wouldn't rush to replace it without better diagnostics.
Perhaps Xylem has some troubleshooting advice. You might try calling them. I will take a quick look for anything helpful
Called Xylem. They say no way to troubleshoot. Could be the control box (about $300) or perhaps the display panel (about $225). I would have to lift the entire floor area to replace the control box. No really good options. I may just break the hot wire to the panel and install a toggle switch to be able to stop the display from flashing. Still not sure.
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Mine broke last year and I had never been happy with the accuracy of the OEM. This gauge's sensors are attached to the external side of the holding tank and it is amazingly accurate and simple to install. Scad TM1 tank monitor.They also have multiple tank gauges options if you need to include a fresh water level.
