Tanks misreading?

[JacqueStacy]

Any new 5ers within-ncommand not reading tanks correctly? I used maybe 3 gallons to wash dishes and the once empty grey tank read 1/3 full. New 2020 alpine 3121rs. Anyone know how many gallons in each grey tanks?

[Stumpy75]

The level gauges on tanks are notoriously inaccurate...

[bsmith0404]

Your gray is approximately 40 gallons. The sensors on the tanks are just wires so anything touching them will cause them to read. Also, keep in mind that these are only approximate based on where the wire is.

[chuckster57]

Welcome to the forum

It is true that the gauges can be inaccurate, it also depends on where the sensors are installed at the factory. I've seen tanks go to 1/3 almost instantly and then take "forever" to get to 2/3 and then again very little time to go to full.

If you want to know where yours are at then just measure the amount of water you put into the tank and have someone watch the monitor panel. If you ran the water while doing dishes it may have been more than 3 gallons, and it also depends on how the trailer is plumbed. Is the kitchen sink on a separate "galley" tank?

[JRTJH]

Holding tanks are "long, wide, shallow rotocast shells" that are fitted between the 8 or 10 or 12 inch frame rails. They sit laterally between the frame rails with the "deep end" (to provide flow during emptying) on the driver's side of the vehicle. The "tank sensors" are also positioned on that "deep end of the shallow tank". They would be on the "extreme left" in the lower right drawing below.....

If your trailer is "slightly off level" you can dramatically change the tank reading from empty to half full with only an inch of "off level condition"...

Here's a diagram of a typical holding tank. The sensors would be located on the "deep end of the tank"... You can visualize how just lifting the shallow end 1" could raise the water level at the sensors proportionally more than 1" just as raising the "deep end" by 1 inch could lower the "sensor level" much more than one inch...

Sensors and the "idiot light panel" are, at best, a means to frustrate new owners... Any "seasoned RV'er" will quickly learn to ignore that "tank monitor system" and rely on sight, sound and days in the field which are much more accurate than the "OEM monitor panel"...

[bsmith0404]

Originally Posted by chuckster57

it also depends on how the trailer is plumbed. Is the kitchen sink on a separate "galley" tank?

It is a separate tank.

[chuckster57]

Originally Posted by bsmith0404

It is a separate tank.

I figured it was.

[Markjonesf18]

I agree with your explanation. Curious what you hear when the Grey holding tank is almost full? Any tip would be appreciated.

[JRTJH]

On our shower/bath vanity gray tank, I don't have any sound/sight indication of how full the tank might be. We rely strictly on how many showers we take (count days of dry camping as a means to determine how full that tank is). We can usually go 5 days without a problem as long as it's just DW and me.

On the galley tank, our galley gray tank is directly under the sink. There's the lateral drain, the P trap and a direct pipe down to the tank. We can pull the drain on the sink and as it drains, we can hear a different, higher pitched sound as the tank nears full. DW is much more "tuned into listening" than I am, so I monitor the days and the gurgles of the toilet while she keeps track of how much she puts into the galley tank..

On our trailer, there's a 37 gallon fresh water tank and two 28 gallon gray tanks. Our shower tank almost always fills first, so I "equalize the tanks" during setup for dry camping. That means I open the tank valves so they both flow to fill equally. With 37 gallons of available water, when we "run out of fresh water, I know each tank has roughly 18 gallons in it. That's a total of 20 gallons to go until both tanks are full. As I add fresh water (5 gallon green containers), I keep track of them. When I'm adding the 3rd container of fresh water, I know when the water pump starts "sputtering" our gray tanks have just about 5 gallons until full (2.5 gallons each)...

For me, it's become "automatic" to keep track of gray water tank status that way. It's not a "hassle" but rather second nature on every dry camping trip... I don't think anyone who "uses the tank status panel" can even come close to knowing when they have 2.5 gallons left to go in each tank or can say, "this shower is when the water will back up into the shower pan"..... So, compared to the gauges/idiot lights, just paying attention is a much more precise way to "know without an LED display.....

[travelin texans]

You'll know when the bath grey is full when it backs up into the shower, usually in middle of my shower, or even worse the DWs.
Typically the kitchen/galley, if a separate tank, will be good til the black tank needs dumped.
The toilet will have a very distinctive "burp/gurgle" when you flush so you'll know when it's getting close to full.

[LHaven]

Originally Posted by chuckster57

I've seen tanks go to 1/3 almost instantly and then take "forever" to get to 2/3 and then again very little time to go to full.

This. In my rigs, "1/3 full" has always meant "you used me at all since you emptied me." 2/3 and 3/3 have always been more meaningful. And keep in mind, they usually engineer a little "emergency room" at "full" because you're not watching the gauge every second.

[flybouy]

My experience with the "push to read levels" display....

Fresh Water - works OK for what it is
Gray Water - kinda works
Blank Tank - reads 3/4 no matter what
Battery - just a joke in MHO

YMMV

[JacqueStacy]

Thanks everyone! I should have been more specific. The 5th wheel is new. We are not new to rving or tanks. I hoped the tank readers would read correctly in the beginning. I appreciate all the quick responses. Our last unit was 10 years old and worked when we first purchased. .