Cleaning fresh water tank level sensors?

[Wconley]

Has anyone found a way to clean the fresh water tank sensors? We recently picked up a 2009 27FB and noticed the fresh tank monitor seemed to show it was running out of water quickly. I worried there might be a leak but today I started with a full tank and measured water pumped from the tank. After drawing 2 gallons the monitor showed 1/2 full and continued down every gallon to show a flashing empty by 9 gallons removed. This will make dry camping a nervous affair so I would like to fix the monitor readings. Has anyone found a method for cleaning or otherwise rectifying the fresh water sensors? Thanks.

[Protagonist]

If your fresh tank is wide and long, but not very deep, then it will be very sensitive to even the slightest inconsistency in leveling your trailer. Think of it as trying to fill a skillet instead of a pot for a mental image of the problem. The skillet might look full to the brim on one side and half empty on the other side if it's not exactly level, when the reality is somewhere in between, whereas the pot right next to it would look full to the brim on one side and nearly full on the other, simply because the pot is much deeper for the same fluid capacity. So for a given tank capacity, the deeper the tank, and the narrower it is horizontally, the more accurate the gauge will be; the wider and shallower it is, the less accurate the gauge.

My point is, it may not actually be a problem with the tank sensors. And in point of fact, if your tank only contains clean, drinkable water, the sensors shouldn't need cleaning, even if they're in-tank sensors and not external sensors stuck on the side.

Side note, for dry camping, it may be more important to accurately monitor the gray tank level than the fresh tank level. Not all places allow you to dump the gray tank on the ground near your trailer so you can't always dump the gray tank without moving the trailer, but you can always use a 5-gallon water can (or several of them) to add more fresh water when you run out, without moving the trailer.

[Wconley]

Thanks Protagonist. Currently the trailer is in our driveway and I did check level carefully before I started. Even then I don’t expect perfect readings. However, having the tank show half full after drawing 2 out of 39 gallons and empty by 9 gallons is off by a little more than I would like. The gray tank, while not being perfectly linear will give me an indirect indication of fresh water level. We’re still getting used to the trailer so eventually we will get a sense of how long we can go on all the systems.

[AWCHIEF]

OP, I have tried several of the old home methods found on the internet and a couple of chemical additives that are marketed for the express purpose of cleaning the tank sensor and restoring them to proper operation. Nothing I have found works for me.

[Wconley]

Thanks Michael. I did find a thread on replacing the sensor of a 27FB which may be my option after research on cleaning. Every day we learn something new.

[CAV]

I have a 2004. There is a procedure to recalibrate the monitor. Involves filling the tank; button sequence, drain the tank, etc. It seems the fresh water is always “full”; grey and black tanks sensor seems fairly accurate.

[Silver.Sanctuary]

Originally Posted by Protagonist

If your fresh tank is wide and long, but not very deep, then it will be very sensitive to even the slightest inconsistency in leveling your trailer. Think of it as trying to fill a skillet instead of a pot for a mental image of the problem. The skillet might look full to the brim on one side and half empty on the other side if it's not exactly level, when the reality is somewhere in between, whereas the pot right next to it would look full to the brim on one side and nearly full on the other, simply because the pot is much deeper for the same fluid capacity. So for a given tank capacity, the deeper the tank, and the narrower it is horizontally, the more accurate the gauge will be; the wider and shallower it is, the less accurate the gauge.

My point is, it may not actually be a problem with the tank sensors. And in point of fact, if your tank only contains clean, drinkable water, the sensors shouldn't need cleaning, even if they're in-tank sensors and not external sensors stuck on the side.

Side note, for dry camping, it may be more important to accurately monitor the gray tank level than the fresh tank level. Not all places allow you to dump the gray tank on the ground near your trailer so you can't always dump the gray tank without moving the trailer, but you can always use a 5-gallon water can (or several of them) to add more fresh water when you run out, without moving the trailer.

With the advent of Barker "Blue Boys" and subsequent manufacture by other companies, it is not necessary to move your trailer to empty the gray tank.
In Yellowstone Campgrounds that had no dump stations, I was able to use the water pump function of the mascerator to pump gray water into the blue boy sitting in the back of my truck and use the same mascerator pump to pump the gray water into the flush toilet of the park latrine through a garden hose. Not a drop of gray water was lost in the transfer, and it made the use of the shower in the trailer functional for at least 'marine showers' and hair washing. In Boondocking areas you might have to drive further to dump in a legitimate location, but you don't have to move your trailer...

[Wconley]

Originally Posted by CAV

I have a 2004. There is a procedure to recalibrate the monitor. Involves filling the tank; button sequence, drain the tank, etc. It seems the fresh water is always “full”; grey and black tanks sensor seems fairly accurate.

I’m getting interested in giving this a try to see if it’s just a calibration thing.

[Protagonist]

Originally Posted by Silver.Sanctuary

With the advent of Barker "Blue Boys" and subsequent manufacture by other companies, it is not necessary to move your trailer to empty the gray tank.

Senior moment. Completely forgot about those since it's not terribly practical to tote one around in an Interstate.

But the totes have a caveat, too. Whatever tote one buys, it needs to either be larger than the fresh tank capacity, or larger than the gray tank capacity, whichever is less, so one doesn't run the risk of overflowing the tote. Or unless one fills it with a macerator pump where the flow into the tote can be interrupted when the tote is full even if the gray tank isn't yet empty.