# Propane Gas question - Checking the level? **URL:** \ **Category:** Factual Questions\ **Created:** [December 29, 2002, 2:24pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502 "2002-12-29T14:24:03Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 29, 2002, 2:24pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/1 "2002-12-29T14:24:03Z")
After a search of the boards I only found that the gas ‘smell’ will get noticabally stronger when the tank is about 10% fuel remaining. Is there some other way I can get an idea how full the tank is? Will a stud finder work? how about using the gas rapidally and somehow find the chenge in temp inside the tank denoting the gas/liquid line? Any of these work, any other suggestionns? ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [December 29, 2002, 2:52pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/2 "2002-12-29T14:52:00Z")
[These guys](http://www.stressproducts.com/hmoffice.htm) sell a liquid crystal strip that changes color at the level of the liquid propane inside the tank. Just stick it on the tank. ---
**Author:** ![beagledave](https://avatars.discourse-cdn.com/v4/letter/b/6de8d8/32.png) [@beagledave](https://boards.straightdope.com/u/beagledave)\ **Post date:** [December 29, 2002, 3:07pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/3 "2002-12-29T15:07:26Z")
Depending on the temp/humidity outside…you may be able to visually see the condensation line of demarcation even without the temp strip ---
**Author:** ![Anachronism](https://avatars.discourse-cdn.com/v4/letter/a/e56c9b/32.png) [@Anachronism](https://boards.straightdope.com/u/Anachronism)\ **Post date:** [December 29, 2002, 3:29pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/4 "2002-12-29T15:29:06Z")
If you are talking about a small propane tank you could weigh it, some gas grills come with a built in scale for this purpose. My larger propane tank for my gas fireplace has a guage on it, perhaps you could add one. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 29, 2002, 5:04pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/5 "2002-12-29T17:04:20Z")
It is a large propane tank used for hot water and cooking. I wouldn’t think a gague (based on pressure) would work unless all liquid was gone. Perhaps the strip would work. The condensation method hasn’t worked in the winter ---
**Author:** ![chique](https://avatars.discourse-cdn.com/v4/letter/c/4491bb/32.png) [@chique](https://boards.straightdope.com/u/chique)\ **Post date:** [December 29, 2002, 8:10pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/6 "2002-12-29T20:10:11Z")
> [@](#): > > \*Originally posted by k2dave \* > **It is a large propane tank used for hot water and cooking. I wouldn’t think a gague (based on pressure) would work unless all liquid was gone.** I don’t know anything about smaller tanks, but why wouldn’t a gauge work? The one on the 300 gallon tank in our yard is at 85% right now. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [December 29, 2002, 9:18pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/7 "2002-12-29T21:18:09Z")
Alton Brown of FoodTV’s Good Eats showed a way. Take a cup of boiling water. Pour it down the outside of the tank. After a few seconds you’ll be able to feel with your hand where the tank goes from hot to cool. That’s the level of the gas. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 29, 2002, 10:15pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/8 "2002-12-29T22:15:56Z")
thanks **AskNott** that’s the one I was looking for (cheap). I never bought into the gauges because I can’t understand how they work. I would think the pressure should be constant till you are out of liquid. Unlike CNG (compressed natural gas) which the pressure decreases as you use it. ---
**Author:** ![Jonathan\_Chance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jonathan_chance/32/701_2.png) [@Jonathan\_Chance](https://boards.straightdope.com/u/Jonathan_Chance)\ **Post date:** [December 29, 2002, 10:27pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/9 "2002-12-29T22:27:45Z")
The gauge on mine (500 gallons used for cooking, heating and the dryer) has a % full marking. Works like a charm. Doesn’t yours? I thought they were all made to the same standard. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 29, 2002, 11:05pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/10 "2002-12-29T23:05:17Z")
No gauge ---
**Author:** ![Jonathan\_Chance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jonathan_chance/32/701_2.png) [@Jonathan\_Chance](https://boards.straightdope.com/u/Jonathan_Chance)\ **Post date:** [December 30, 2002, 12:38am UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/11 "2002-12-30T00:38:34Z")
None at all? Who’s your service company? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 30, 2002, 12:49am UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/12 "2002-12-30T00:49:35Z")
Agway ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [December 30, 2002, 1:13am UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/13 "2002-12-30T01:13:09Z")
Our guages at work are magnetic float guages. I’ll explain if interest exists. 😉 Peace, mangeorge ---
**Author:** ![Alereon](https://avatars.discourse-cdn.com/v4/letter/a/ecd19e/32.png) [@Alereon](https://boards.straightdope.com/u/Alereon)\ **Post date:** [December 30, 2002, 1:50am UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/14 "2002-12-30T01:50:19Z")
Color me paranoid, but is it really SAFE to be pouring boiling water over a propane tank? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 30, 2002, 2:00am UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/15 "2002-12-30T02:00:39Z")
Totally safe unless it pours on your toes ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [December 30, 2002, 2:20am UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/16 "2002-12-30T02:20:01Z")
Color me can’t spell gauge. ---
**Author:** ![The\_Mermaid](https://avatars.discourse-cdn.com/v4/letter/t/a183cd/32.png) [@The\_Mermaid](https://boards.straightdope.com/u/The_Mermaid)\ **Post date:** [December 30, 2002, 11:08am UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/17 "2002-12-30T11:08:21Z")
File this in the stupid questions department if you want but how do you know when to refill if you don’t have a gauge? My 300 gallon propane tank, used for heating and water, has a gauge under the little hood. It would be a big deal if it ran dry. My 20 gallon tank on the barbeque does not have a gauge but it is no big deal if it runs out. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 30, 2002, 1:23pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/18 "2002-12-30T13:23:18Z")
OK, OK I will look fo rthe gauge. ---
**Author:** ![SavageNarce](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@SavageNarce](https://boards.straightdope.com/u/SavageNarce)\ **Post date:** [December 30, 2002, 1:33pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/19 "2002-12-30T13:33:57Z")
I use the hot water trick, but note that it does not have to be boiling - hot from the tap works just fine. The amount of heat that gets absorbed by the gas (as opposed to the metal tank itself) is minimal, so no danger of raising the pressure in the tank to a dangerous level just by pouring a couple of cups of hot water on the tank. Now if you had a water shortage and wanted to use a blowtorch instead…:eek: ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [December 30, 2002, 1:35pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/20 "2002-12-30T13:35:38Z")
Just to add this is in my vacation house so It’s not like I can just go out back and check it right now. I’ll let you know if it does and how the hot water method works. As for how they fill it w/o a gauge, I though the vavle has a device in it that will stop the refill once it gets to a certain level, [Next page](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502.md?page=2)