Water tank 'fill' meter - what does it measure?

[Karlton]

Hey gang - has anyone conducted an analysis of what the factory water tank meter measures? I'm interested to know how much water I have when it reads 1/3 and 2/3. Full and empty seem intuitive if they represent the value of 20 and 0, but I'm not quite sure about the other measurements because there could be a range of values these numbers represent. Knowing the range of values represented by 1/3 and 2/3 will help trip planning.

If this has been covered, please direct me to the post.

Cheers!

 

[PackRat]

It would seem some old-school detective work might help here.

OK, you have Empty, 1/3, 2/3 and Full, right?

If the tank holds 20 gallons that would mean 1/3 was about 7 gallons and 2/3 was 14 gallons... sorta.

OK....drain the tank and water your flowers....then put in five gallons and check the meter. if it is below the 1/3 mark add a gallon at a time until you have 1/3 showing. Now you know what "1/3" means.

Keep going until you know what 2/3 and then what Full means on the meter.

However, the pump pickup tube is probably a bit higher than the drain so keep that in mind!

 

[PaulT]

In a Truck Camper Magazine mods article a year or three ago, someone suggested using a water flow meter to load your water tank with only enough water for the trip to reduce unneeded weight. This is one meter recommended: https://www.amazon.com/RAINWAVE-WATER-TIMER-SAVE-METER/dp/B007NHS9M4?ie=UTF8&*Version*=1&*entries*=0

Starting with an empty tank, run water into tank through the flow meter. Watch the factory water indicator LEDs and note the flow meter reading when each LED turns on. That should give a reasonable value for your camper. I can't imagine that the indicators being very repeatable but it should be ok as an estimate. One can hope it is better than the battery charge indicated by the other button.

Paul

 

[Casa Escarlata Robles Too]

Why make it complicated.
Fill the tank from 1 gallon bottles as needed.
Frank

 

[Karlton]

Thanks. I might get the water meter so I know how much I have in the tank and correlate the gallons with the factor meter.

 

[esimmers]

The built-in meter is only a rough guide to water level since it uses only 3 or 4 sensors arranged vertically along the end of the tank. Once the water level drops below one sensor, there's no change in the display until the level drops below the next lower sensor. The water tank in my 09 Hawk is translucent so if I open the seat lid for the camper battery I can see the end of the water tank and observe the actual level of the water. Works great for me.

 

[Casa Escarlata Robles Too]

Visually checking the tank,if you can works.
I can view mine I think if I pull the drawer out.
Frank

 

[XJINTX]

I use the flow meter and I'm actually impressed on how well it works... pretty accurate. As mentioned on a short trip I am able to take just 5 or 10 gals and not overload or waste water emptying when I get home.

 

[smlobx]

Just an additional data point to consider when you conduct your experiment but be sure to have your rig level for the best results...

 

[rando]

I was also unhappy with the lack of resolution from the 'stock' water meter and replaced it with a continuous capacitive water meter that gives ~1gal resolution. The space between 1/3 and empty for us is the difference between stay out for another 2 days or head to town for water in the morning.

I would agree with the others who have said that the best option is to be able to look at the side of the tank - and I have seen some people mill a slot into their cabinetry for this purpose. Unfortunately on the flatbed models, you can't really see the tank and it is behind the electrical compartment so you can't add a slot. Thus the capacitive water level sensor and a new control panel.

Here is the new control panel I made up to show the water level amongst other things:


[sharedmedia=core:attachments:27036]



[sharedmedia=core:attachments:27035]

 

[Wallowa]

Another view...off road beyond most supplies we are concerned with the LCDs; what will we run out of first that we need.

Just considering the Hawk: Electricity, water, propane. We carry extra water, battery lights, down sleeping bags and a backup camping stove so even if our two batteries can't reach a sufficient charge [solar or truck alternator] to power the water pump or start the furnace we can stretch our stay or egress time.

What puzzles me is to go off road with less that the 26 gallons of water that is possible in our Hawk. Water is the limiter not weight of the water. If the weight of the water is more than the truck/FWC combo can handle then the combo needs to be re-evaluated. The "dummy lights" in the Hawk serve us well and we can estimate when it is time to search for a water source be that a stream, lake or municipal water system. Yes, we carry a water filter; laborious to filter gallons, but an option to extend our stay.

Just my take and your needs may dictate carrying less water. Interesting to read this discussion. And of course I might be wrong.

Phil

 

[XJINTX]

Phil, I totally agree with your position. If I'm on a off grid trip I always fill my tanks when available even if only used a few. Just as I try and top off with Diesel when I can just in case.. However here in TX we do a lot of just weekend getaways to National Forests, COE primitive and such. No where near off the grid and facilities are usually close. Just nice to have enough water on board to make coffee and such. I just don't like leaving water in my tanks even if only for week or two. It's just a waste to drain a mostly full tank because I was prepared. The flow meter helps me to gauge and not waste.

 

[fireball]

I'm not sure why they don't just route a cutout into the cabinet housing the water tank and let you physically see the water in the tank! I've been meaning to do that but the most we've stayed out at one time without access to supplies was 4 days.

 

[Mickey Bitsko]

Kind of late to the discussion but, one way to check and post a note, fill the tank then drain a couple gallons at a time,note guage repeat till empty, save the water, refill tank. No wasted water and post findings in camper. Seems easy enough.

Mickey

 

[DanBuffalo]

Had this same question regarding my 2021 Hawk (with water heater). So I ran this experiment with the water heater out of the loop (I closed off both the upper and lower water heater drain cocks):

1. Truck placed on level ground.
2. Filled the empty 20 gallon tank, 1 gallon at a time, until tank was full, and monitored
the "Full-2/3-1/3-E" inside red-light meter after each gallon added.
3. Opened the small drain cock on the outside of the camper, measured 1 gallon outflow one gallon at a time and concurrently monitored the meter.
4. Continued this process until drain outflow completely stopped, recording the results at each gallon.
5. Put the camper on a steep grade, aft end pointing downwards, and measured the remaining outflow.

This experiment gave me two sets of readings (on filling, and then on emptying). I ran the experiment twice, and got four sets of readings.

Being a retired hydrologist (This is why I had time to run this experiment ), I expected exactly identical readings each time, but this was not the case which I thought was peculiar. Here are my findings (averaged):

[SIZE=10pt] Min [/SIZE][SIZE=10pt] Max[/SIZE]
[SIZE=10pt]Full Light: 16 – 20 gallons remaining[/SIZE]
[SIZE=10pt]2/3 Light: 11 – 15.5 gallons remaining[/SIZE]
[SIZE=10pt]1/3 Light: 4 – 10.5 gallons remaining[/SIZE]
[SIZE=10pt] E Light: 0 – 3.5 gallons remaining[/SIZE]
[SIZE=10pt] +6 gallons in WH[/SIZE]

Based on these results, I never fire up the water heater after the "E" light comes on, even though, hypothetically, there may be 3.5 gallons in the tank and 6 gallons in the water heater.

Hope this is helpful.

 

[craig333]

Heck, its more accurate than I expected

 

[wicked1]

Here is the new control panel I made up to show the water level amongst other things:

Rando,
Did you design/build that? And the panel for it?
If so, are you an EE?
The panel looks like modular synth panels I build....

It looks great... I have many questions.. well, since I've already gone OT, I guess it's a little microcontroller of some kind, and you've programmed it to monitor and display the temp/water/voltage?

-just realized I'm replying to a 5 year old post... But still wondering.

 

[AWG_Pics]

Had this same question regarding my 2021 Hawk (with water heater). So I ran this experiment with the water heater out of the loop (I closed off both the upper and lower water heater drain cocks):

1. Truck placed on level ground.
2. Filled the empty 20 gallon tank, 1 gallon at a time, until tank was full, and monitored
the "Full-2/3-1/3-E" inside red-light meter after each gallon added.
3. Opened the small drain cock on the outside of the camper, measured 1 gallon outflow one gallon at a time and concurrently monitored the meter.
4. Continued this process until drain outflow completely stopped, recording the results at each gallon.
5. Put the camper on a steep grade, aft end pointing downwards, and measured the remaining outflow.

This experiment gave me two sets of readings (on filling, and then on emptying). I ran the experiment twice, and got four sets of readings.

Being a retired hydrologist (This is why I had time to run this experiment ), I expected exactly identical readings each time, but this was not the case which I thought was peculiar. Here are my findings (averaged):

[SIZE=10pt] Min [/SIZE][SIZE=10pt] Max[/SIZE]
[SIZE=10pt]Full Light: 16 – 20 gallons remaining[/SIZE]
[SIZE=10pt]2/3 Light: 11 – 15.5 gallons remaining[/SIZE]
[SIZE=10pt]1/3 Light: 4 – 10.5 gallons remaining[/SIZE]
[SIZE=10pt] E Light: 0 – 3.5 gallons remaining[/SIZE]
[SIZE=10pt] +6 gallons in WH[/SIZE]

Based on these results, I never fire up the water heater after the "E" light comes on, even though, hypothetically, there may be 3.5 gallons in the tank and 6 gallons in the water heater.

Hope this is helpful.

Very interesting. Makes a lot of sense. Thanks for doing the careful measurements and sharing the results.

 

[UncleDougie]

Why make it complicated.
Fill the tank from 1 gallon bottles as needed.
Frank

I agree. KISS "Keep It Simple Stupid" empty the tank and then get a 5-gallon fill bucket and fill. Then make your own marks on the next the little view port with 5-gal marks.