39 Gallon Propane Tank - How low have you let yours go?

LK23 · 11-21-2009, 01:12 AM

I have a 39 gallon propane (31 usable gals.) tank on my Itasca Horizon 40AD. My tank gauge shows about 20 percent remaining and I expect the red light on the inside monitor to come on soon. In the past, I have re-fueled the propane at this point. I have another ten days at this location and I am hoping I can hold out and get propane enroute to the next location.

Using the tank gauge, how low have you gone with your propane level?

MonacoMama · 11-21-2009, 01:41 AM

I have a couple of questions for you...

How often are you using it to cook?
Are you using the furnace to heat the rig...and how often is it running?
Are you using it or are you using electric for your water heater?

You can probably last the 10 days without a problem unless you are running the propane appliances (like the furnace and water heater with propane) all of the time.

I have run my same size tank for many days after my red light came on.

MrTransistor · 11-21-2009, 04:13 AM

Hello LK23,

I believe your tank is actually 31 total gallons and only holds 80% of that 31 gallons or 24.8 gallons. The part number for you tank and mine is the same (144251-01-000) and the brochure lists the capacity as 31 gallons with a note 4 that says “Capacities shown are tank manufacturers listed water capacity (W.C.). Actual filled LP capacity is 80% of listing due to overfilling prevention device on tank.” On mine this holds very true since a bone dry tank will take 23.6 gallons. Unless you swapped out tanks, that is.

I ran tests, and keep this record of the inside indicator (in color), outside gauge (expressed as a fraction), and date. There was other information but it’s not relevant. Of course, your gauge could be calibrated completely different from mine but this should give you an idea of what to expect. I have a .PDF that I created that will accurately tell you what fraction the meter reads which may be helpful. I figured that there were 5 gallons left after the tank gauge hit 0 and as much as 10 gallons after it went red on the inside meter.

Being out and not knowing exactly what to expect can be just a little unnerving. That is why I prepared this data and keep it on my computer for reference when we are on the road. Perhaps you could use this example to create your own tank guide when you’re settled in somewhere.

http://www.irv2.com/attachments/phot...Meter_data.jpg

http://www.irv2.com/attachments/phot...m/LP_Meter.jpg

MonacoMama · 11-21-2009, 11:04 AM

MrTransistor

... I can tell you that we do have a 39 gallon tank with holding capacity of just over 31...Our specs state it as a 39 gallon and I know I have taken down to almost nothing

(not by choice). The guy who filled the tank was amazed when he put 29 gallons into it.

I was just thankful I was able to get the propane on the day that I did...

With that being said...I cannot vouch for what LK23 actually has...

LK23 · 11-21-2009, 11:21 AM

Mr. Transistor,

Thanks. You are doing what I am attempting to do in calibrating my propane gauge. I was not able to read the small print on your bar chart.

My manual says I have a 39 gallon tank with 31 gallons usable, so I am scratching my head on that one. I will include the PDF file of my initial attempt to calibrate.

MrTransistor · 11-21-2009, 09:28 PM

Hello MM,

I can believe that but as I stated, the brochure for our coach, an 04 Winne, states 31 –20%, and the parts books for both the 04 40WD and the 05 40AD (LK’s coach) list the same part number for the propane tank of 144251-01-000. Take my word for it, we all wish we had 39 gallon tanks! Or 50 would work well.

Hi LK,

Try this link to the Photo that I posted, http://www.irv2.com/photopost/showfull.php?photo=13000 . I’m not sure why the link in the post above is of such a poor resolution. To come up with the fractional tank readings, I used my digital camera on a monopod with appropriate settings for flash and focus and stuck it under the slide with a 10 second shutter delay to get a picture of the tank’s meter. Then I compared the picture of where the needle was with the .PDF image in the post above that I created in CAD. It beats crawling under the slide to look at the gauge. If you can catch yours changing from say green to yellow (2/3 light just goes out) and the tank gauge is reading 1/2 then yours would seem to be calibrated pretty close to mine and you can take it from there. If not, you should still be able to apply some sort of offset to the readings to get a reasonably close approximation of what’s left in the tank.

LK23 · 11-21-2009, 11:14 PM

Mark,

The spec sheet I received with my 40AD states I have: LPG (Fillable to 80%) 31 gal.

And, my manual states: 31 gal. (39 gal. w.c.)

That said, I really think I have 31 usable gallons.

autofish · 11-22-2009, 01:53 AM

Mark my tank also is stamp 39 wc gal so times 80% is 31 gal and I have had to put in 28 gal to refill when almost emty. So I also feel my tank is a 39 gal tank.

MonacoMama · 11-22-2009, 01:54 AM

All I can say is - good luck with your next ten days of propane...
If you can- I would also take the tank down as low as you can...and if you are able to fill it above 25 ..then you know you have the bigger tank!

Good Luck and have a great Thanksgiving to you & MrTransistor!

robbstein · 11-22-2009, 10:47 AM

We have the 40K 2003 Ultimate Advantage and also have the 39 gallon tank. Generally, I've filled it when the tank gauge gets below 1/4. By this time the inside gauge has gone red for awhile. I think the most I've ever put in it was 26 gallons and the tank gauge was below 1/4. You should have no problem lasting 8-10 days if you are not using the furnace for heat. The water heater when used intermittently and for cooking usually will not deplete the tank that much.

Lorna · 11-22-2009, 07:42 PM

I don't think you would hurt anything by running your tank completely empty. We did and then added a fitting that allowed us to run the little BBQ tanks instead. We recently filled our onboard LP tank for the first time since we bought the RV (ours is an old crate). Only down side to draining the tank down to empty is getting air in the line. The good thing is that we now know how much our tank holds (in our case 9 gallons).

MrTransistor · 11-22-2009, 07:53 PM

Hi All,

On my list of ‘to do’s’ is check the tank markings. I have run the tank completely dry several times before, no furnace, hot water, or stove and the fills have been 25.1, 25.0, 23.8, 25.4, 24.2, 25.6, 23.6, 25.6, 25.1, & 24.4 gallons. Many more fills than this but these are the ones when we knew we were completely empty. Why am I not surprised that some coaches say 31 and have 39 and others say 39 and have 31? All I do know at this point is my tank says ‘GAL 31.6’. Now I need the rest of the info.

mudpuppy · 11-22-2009, 08:29 PM

Quote:

Originally Posted by MrTransistor

Hi All,

On my list of ‘to do’s’ is check the tank markings. I have run the tank completely dry several times before, no furnace, hot water, or stove and the fills have been 25.1, 25.0, 23.8, 25.4, 24.2, 25.6, 23.6, 25.6, 25.1, & 24.4 gallons. Many more fills than this but these are the ones when we knew we were completely empty. Why am I not surprised that some coaches say 31 and have 39 and others say 39 and have 31? All I do know at this point is my tank says ‘GAL 31.6’. Now I need the rest of the info.

31 gal tank when empty will hold about 24 gal due to the 80% fill regulation.

MrTransistor · 11-24-2009, 12:24 AM

Hi All,

Either I got short changed or Winne used the 31 gallon Water Capacity tank on all 2004 Horizon 40WDs. I finally was able to get the data from the tank and also took very accurate measurements and did the math (see below). The tank is most definitely 31 / 25 gallons as is evident by the fills and the tank markings. Since we have owned 3 coaches, I wanted as large a propane tank as we could get, but Winne does not offer the option of a larger tank. What we get is what we got. It just would be nice to have more propane on board for camping. We use mostly electric oil filled heaters when we are parked.

SER No. 1876679
CERTIFIED BY

MANCHESTER
TANK

(?)W MAWP312 PSI@650
RT-4 MDMT20F @312PSC
CAT#68128 YR2004
CRN L4885.5C
8H 102 GAL31.6
HD 049 21SE
0012 0L68 88SAT8.5FT

FOR LP GAS ONLY-ABOVE GROUND
ETC. ETC. ETC.

TANK MEASUREMENTS
Outside Circumference 38"
Body Length 61"
Curved End Cap Length 4"
Total Length 69"
Metal Thickness est. 3/16"

V. of cylinder = Pi*r Sq.*L = 6581.6 Cu.In.
V. of ends = (4/3 Pi*r Cu.)* ~2/3 = 562 Cu.In.
Total V. = 7143.6 Cu.In.
1 Gal = 231 Cu.In.
Total Capacity = 30.925 Gallons
%80 = 24.75 Gallons

Roadking · 11-24-2009, 09:29 PM

We have the 39 gal tank and we have ran it down to the "E" on the external gauge several times. I don't trust the idiot lights as the red light comes on when the external gauge shows about 1/4 remaining, however, the tank is actually about 1/2 full at that time. When the external is close to "E" it takes about 24 -26 gallons and the most I have put in is 27 gallons.

We use the electric water heater as much as possible so the only big draw is the furnace. Durning the night we like it cool inside so we run our furnances in the mid 50's. At this temp, if the morning temps are in the mid teens the furnance(s) will empty a full tank in just under 2 weeks. How long your remaining propane will last is a function of how high you set your furnance thermostats and how cold it is outside.

We full time and Our last propane fill was last July, in Missoula MT, where I paid 0.99 per gallon. Since then we've used the furnances some, (maybe 2 dozen evenings) use the cooktop all the time, and we used the propane water heater a few times when dry camping. We still have about 3/8 tank left. We're currently in Las Vegas and only use the propane furnance in the bed room and the cooktop. The remaining 3/8 tank should last us about a month and I dread the thought of refilling as I just noticed a nearby service station has propane listed at $4.39 per gallon!!!!

LK23 · 11-25-2009, 10:29 AM

Well, to end this confusion, I crawled under my coach and took a photo of the tank label. It says Cat# 68128 and 31.6 gal. This left me wondering, is the 31.6 gallons before or after the 80% is applied. I called Manchester, the tank manufacturer, and they told me the tank is 31.6 gallons WC (meaning water capacity). The propane capacity is 80% of that, or 25.3 gallons. The manual that came with my Itasca 40AD is WRONG, it is not 39 gallons WC. The spec. sheet that came with my coach says: LPG (Fillable to 80%): 31 GAL. So, the spec sheet was somewhat correct. It should have said 31 GAL WC.

Mark, I should not have doubted you. You were correct after all.

cbeierl · 11-25-2009, 11:21 AM

From inspecting the brochures it seems that the Journey & Meridian (called the Horizon before 2004) had 39gal (WC) tanks prior to 2006, 31gal (WC) tanks in 2006 & 2007, and then 28gal (WC) tanks since 2008.

The Vectra & Horizon had 31gal (WC) tanks from 2004 through 2008. The 2009 models appear to have had 30gal (WC) tanks.