# What's the best way to check for a leak in a propane line? **URL:** \ **Category:** Factual Questions\ **Created:** [October 8, 2011, 2:27pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994 "2011-10-08T14:27:41Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![UltraVires](https://avatars.discourse-cdn.com/v4/letter/u/ecccb3/32.png) [@UltraVires](https://boards.straightdope.com/u/UltraVires)\ **Post date:** [October 8, 2011, 2:27pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/1 "2011-10-08T14:27:41Z")
Here’s the setup: It’s a rural house in the middle of nowhere. I’ve got a small stove/oven combination that is connected to a propane line that runs under the house about 30 feet where I connect it to a propane tank. Typically a tank lasts for about 2 months. Lately, it last 2 weeks. There has to be a leak somewhere. I don’t smell propane in the house or around the tank. Is there a device that will push air through the line and help me figure out where the leak is? Thanks. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [October 8, 2011, 2:31pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/2 "2011-10-08T14:31:55Z")
Have you checked all fittings using soapy water? ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [October 8, 2011, 2:37pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/3 "2011-10-08T14:37:52Z")
If you have a large tank, 250 or 500 gallons that’s filled from a truck, I’d contact those folks and ask for help. There are electronic sniffers that can trace for leaks, but only the service folks or fire department would have those. Otherwise you’d mix up soapy water and trace the line slopping the soapy mixture on with a brush and looking for bubbles. Propane is heavier than air so will tend to collect in low spots. It also is not breathable in high concentrations, so be very careful of confined spaces or low areas. Make sure you have someone there to watch and ensure you don’t run into trouble. ---
**Author:** ![UltraVires](https://avatars.discourse-cdn.com/v4/letter/u/ecccb3/32.png) [@UltraVires](https://boards.straightdope.com/u/UltraVires)\ **Post date:** [October 8, 2011, 2:41pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/4 "2011-10-08T14:41:39Z")
Thanks for the quick responses. No, it is not a large tank filled professionally. I’ve never heard of this soap trick. You say I should mix up soapy water, brush it on the outside of the line at the fittings and check for bubbles? Not to be dense, but wouldn’t there be bubbles everywhere in soapy water? ---
**Author:** ![davidm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/davidm/32/225_2.png) [@davidm](https://boards.straightdope.com/u/davidm)\ **Post date:** [October 8, 2011, 2:43pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/5 "2011-10-08T14:43:11Z")
Take care of this soon. if you have propane gathering under the house, you could have a dangerous situation. ---
**Author:** ![UltraVires](https://avatars.discourse-cdn.com/v4/letter/u/ecccb3/32.png) [@UltraVires](https://boards.straightdope.com/u/UltraVires)\ **Post date:** [October 8, 2011, 2:46pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/6 "2011-10-08T14:46:06Z")
> [@davidm](#): > > Take care of this soon. if you have propane gathering under the house, you could have a dangerous situation. Thanks. Right now, the tank is empty and disconnected, so no danger of propane collecting right now. This weekend we will be doing all of the cooking on the grill. But when I get the tank filled and reconnected, I want to start right away at finding the leak. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [October 8, 2011, 2:52pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/7 "2011-10-08T14:52:46Z")
> [@jtgain](#): > > Thanks for the quick responses. > > No, it is not a large tank filled professionally. I’ve never heard of this soap trick. You say I should mix up soapy water, brush it on the outside of the line at the fittings and check for bubbles? > > Not to be dense, but wouldn’t there be bubbles everywhere in soapy water? sort of, but when you mix it don’t agitate it into suds. use a spray bottle and wet down all exposed lines, clamps, crimps and valves. if there’s a leak, you’ll see bubbles _forming_ at the source. They might be very fine bubbles if the leak is tiny, or big ones if it’s more substantial. n.b. the reason the water needs to contain soap is so it can “wet” the surface more completely, and actual form stable bubbles. **ETA:** this is checking for a leak in a tire valve: [![](https://img.youtube.com/vi/i4ZHz4yVhGo/maxresdefault.jpg "Testing for valve stem leak") ](https://www.youtube.com/watch?v=i4ZHz4yVhGo) here’s a bigger leak on a gas line: [![](https://img.youtube.com/vi/SjLkj_-r7Lg/hqdefault.jpg "You might have a gas leak if...") ](https://www.youtube.com/watch?v=SjLkj_-r7Lg) ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [October 8, 2011, 2:53pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/8 "2011-10-08T14:53:29Z")
> [@jtgain](#): > > Not to be dense, but wouldn’t there be bubbles everywhere in soapy water? There will be some bubbles, but you aren’t putting ‘lather’ on the fittings. That is, you’re putting on water containing soap; not a bubble bath. If gas is escaping, then the soapy water at the leak will be bubbling. The purpose of the soap in the water is to make the bubbles more visible than the ones that would be there if you used plain water. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [October 8, 2011, 5:14pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/9 "2011-10-08T17:14:27Z")
a leak at the tank or stove should be smellable it takes very little to smell it, even a loose fitting will have enough to smell. checking the exposed line and fittings will indicate a leak with bubbles. the line is already pressurized with propane to help you find a leak. if the leak is underground you will need to replace the length of line. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [October 8, 2011, 7:55pm UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/10 "2011-10-08T19:55:47Z")
Sounds dangerous. If you can afford it, hire a professional to “sniff” the line and locate any potential leaks. He will use a gas detector to do the “sniffing”, not his nose, btw. ---
**Author:** ![andyleonard](https://avatars.discourse-cdn.com/v4/letter/a/e19b73/32.png) [@andyleonard](https://boards.straightdope.com/u/andyleonard)\ **Post date:** [October 9, 2011, 3:43am UTC](https://boards.straightdope.com/t/whats-the-best-way-to-check-for-a-leak-in-a-propane-line/598994/11 "2011-10-09T03:43:33Z")
Around here, before the Fire Department will sign off a new propane line, you must put a gauge/valve on one end, block off the other and put air pressure in the line while they stand there and make sure it won’t leak down over 15 mins or so. The fittings are less than $10 at the hardware store and you can pump up with a small compressor or bike pump. This will ideally eliminate digging up the line and leave you with just the above ground fittings for the soap test. A good old-fashioned propane house blast will level your house and kill your ass. Do not mess around here.