Propane Tank Hissing: What’s the Cause and How to Fix It

Propane tanks are quite useful. People tend to use them for home heating, cooking, as part of hot water heaters, gas fireplaces, and even for drying clothes. Chances are that you also have a propane tank at your home and that you’re using it regularly. And if so, you’ve probably heard it hiss at some point.

If so, you don’t have to panic. While it’s true that hissing can be a sign of danger, it might simply be a minor issue. So, if you’re trying to find a way to get rid of that annoying sound, you’ve come to the right place. This article will cover the propane tank hissing issue, as well as different methods you can use to get it fixed.

Regular Propane Tank Noises

Before figuring out what to do with your propane tank, you first need to learn to differentiate between various sounds that a tank typically makes. Broadly speaking, they fall into one of these categories:

  • Humming
  • Gurgling
  • Clicking
  • Wobbling or pulsating
  • Squealing
  • Swishing.

Sorting Through the Noises

Let’s go through each of these different noises one by one. If you hear a humming noise, it’s most likely propane moving through the hoses, the appliance burners, or the regulator. This sound is fairly normal, and there’s nothing to be worried about.

If there’s some gurgling, there’s a high chance that the tank is overfilled. Of course, having an overfilled propane tank can be dangerous, but luckily, there are ways you can approach the problem. In fact, even professional propane tank repair experts will direct you to drain the tank yourself in order to get the excess propane out.

At times, air can get trapped in the tank, which can cause a knocking sound. If that’s the case, a professional will explain to you how to get the air out. The procedure is basically similar to the one mentioned in the paragraph above.

What happens if there’s a clicking, a wobbling, or a pulsating sound? Well, that’s just the regulator moving when you switch the appliance on, which is also expected. However, you may also hear clicking when you have a low flow of propane. That’s when the tank essentially locks itself as a safety measure, and if you want it to work normally again, you’ll have to reset it.

Squealing is not that common of a sound, but it can occur. If so, then you probably have a faulty regulator. The best thing to do here is to replace it completely.

Finally, there’s swishing. This sound is also normal, and it occurs when you carry your propane tank around. That’s because the propane within the tank is a liquid, and liquids swish when carried about.  

Testing for Gas Leaks

Now we get to the hissing bit. It should be stressed that not all hissing sounds are necessarily gas leaks, which is the go-to response for most people. For instance, if the tank makes a quick hiss when you first connect or disconnect the hose, that’s normal and isn’t a sign of a leak. What you’re looking for is a continuous hiss, the one that lasts for a while even when the device is off.

Of course, there is one more important indicator that you might have a gas leak. If the hiss is followed by a strong stench of rotten eggs, then you most likely have a leak problem. That’s when you want to get the device fixed as quickly as possible.

So, let’s focus on how you can test for leaks.

Gas Detector Usage

In order to make sure there’s gas leaking out, get a gas detector device (like this one). You can buy one fairly easily online.

Another alternative is to use a gas detection spray. All you need to do is spray it onto all connection parts of the hose, as well as the valve. If you see bubbles forming anywhere, you’ve found your leak.

Bleeder Valve Issues

Did you have your propane tank refilled recently? If so, there’s a chance that the person who did the refilling didn’t close the bleeder valve fully. You can normally tighten this valve by yourself with a flat-head screwdriver. But if you require help, contact a professional just to be safe.

Over-Pressurized Safety Relief Valve

This is possibly the most serious of situations you can come across. When there is too much pressure in the propane tank, some of the gas will escape through the safety relief valve. The second you spot that, make sure to follow these guidelines to the letter:

  • Do not get any open flames close to the safety relief valve;
  • Spray the propane tank sporadically with a hose so you can cool it down a little;
  • If possible, remove the tank from a hot room to a cooler environment;
  • Do not, under any circumstances, try to adjust the safety relief valve;
  • Do not try to close the valve when it’s open;
  • Never try to take a look inside the valve when it’s emitting propane.

After a while, the propane tank will cool down on its own. That’s when the safety relief valve closes, and all the leaks stop. 

How to Fix the Hissing Issue

OK, so now that you know what can cause hissing, when should you react? Well, only if the hissing persists, if there’s a leak, and if you smell a pungent scent coming from the tank. Here are three methods you can apply to your propane tank to stop it from hissing.

Reset the Regulator and All Relevant Connections

Yes, as mundane as it may sound, sometimes a complete reset is what your propane tank needs. Here are the steps you’ll need to follow to reset it:

  1. Turn off the appliance;
  2. Close the propane tank valve completely;
  3. Disconnect the hose from the propane tank (or the appliance regulator);
  4. Inspect the hose or the connector for any signs of damage;
  5. Reconnect either the hose or the regulator to the tank;
  6. Slowly start turning the propane tank on;
  7. Try checking for leaks again using any of the methods above;
  8. Turn the device on, then check for leaks once again.

Problems With the Device

Of course, if the hissing persists, it might not be the tank. Chances are that the problem lies in the device it is connected to. So, just to make sure everything’s alright with the tank, test it with a different appliance. Furthermore, if you have an extra propane tank, try to use it with the same device your hissing tank was connected to first.

What to Do If the Hissing Persists

Sometimes, you’ll reach a point when, even though you did every check under the sun, the propane tank still hisses. If the noise persists, then the issue is probably a damaged OPD valve. At that point, there isn’t much you can do other than replace the whole tank. Contact your local technician and do it as soon as possible. 

Propane Tank Hissing: Final Thoughts

As stated, hissing may be a cause for concern if there’s a genuine gas leak. However, you should always perform all other tests to make sure that it is indeed leaking. Propane tanks tend to make different noises, as stated in this article. So, in order to save money AND get rid of the noise quickly, try using one of the methods described above, and you might just solve the hissing issue in a matter of minutes.

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