Propane Cylinder Safety

How to Check a Propane Tank for Leaks

Checking a propane cylinder and its connection for leaks is a simple but important safety step. A basic bubble test can help identify escaping propane before you light a grill, heater, or other propane appliance.

When should you check?
Inspect for leaks before using a propane cylinder and appliance for the first time each season and whenever you reconnect or replace a cylinder.

What You Need for a Propane Leak Test

You do not need specialized equipment for a basic connection check.

  • Commercial gas leak detector solution, or
  • Thick soapy water
  • A small brush, sponge, or spray bottle for applying the solution
Never test for a propane leak with a match, lighter, flame, or other ignition source.

How to Perform the Bubble Test

1
Make sure the appliance is off
Turn off the appliance controls before opening the propane cylinder valve.
2
Apply the leak-test solution
Apply commercial leak detector solution or thick soapy water around the cylinder valve, regulator connection, and the point where the hose or appliance connects to the cylinder.
3
Slowly open the cylinder valve
Slowly open the propane valve while watching the areas covered with solution.
4
Watch for bubbles
Bubbles that continue to grow or repeatedly form can indicate escaping propane.
5
Close the valve if you find a leak
If bubbles form, close the propane cylinder valve and stop using the appliance.
6
Correct the connection and retest
If the leak is at a removable connection, follow the appliance manufacturer’s instructions for properly reconnecting or tightening it, then perform the bubble test again.
If bubbles continue to form after the connection has been properly corrected, close the cylinder valve and stop using the equipment.
Contact your propane retailer or a qualified service technician.

What Do Bubbles Mean?

A few bubbles created when you first apply the solution are not necessarily a leak.

The warning sign is bubbles that continue to grow, reform, or expand while the propane valve is open.

That indicates gas may be escaping from the connection.

Where Should You Check for Leaks?

Focus on places where propane equipment connects together.

  • Around the cylinder valve
  • At the regulator connection
  • At hose fittings
  • Where the hose connects to the appliance
  • Around any other removable propane connection

What If the Cylinder Itself Is Leaking?

Do not attempt to repair, weld, patch, modify, or disassemble a propane cylinder.

If you believe the cylinder valve, pressure-relief device, body, or another permanent component is leaking, stop using the cylinder and contact a propane retailer or qualified propane professional.

Never attempt to repair or modify a propane cylinder yourself.

What If You Smell Propane?

A bubble test is intended for routine connection checks. It is not a method for investigating an obvious or significant gas leak.

If you strongly smell propane, hear escaping gas, see a vapor cloud, or otherwise suspect a significant leak, avoid flames and ignition sources and move away from the area.

If you believe there is an active propane leak or immediate danger, move to a safe location and contact emergency services.

Inspect the Cylinder Before Use

A leak test is only one part of checking a propane cylinder.

Before connecting a tank, also look for:

  • Severe rust or corrosion
  • Deep dents or bulges
  • Cracks or cuts
  • Valve damage
  • Damage to the protective collar
  • Damage to the cylinder base or foot ring
Quick Leak-Test Checklist
  • Turn the appliance off.
  • Apply leak-test solution to the connection.
  • Slowly open the propane valve.
  • Watch for bubbles that grow or continue forming.
  • Close the valve if a leak is found.
  • Correct the connection and retest.
  • Stop using the equipment if the leak continues.

Frequently Asked Questions

Can I use soapy water to check for a propane leak?
Yes. Thick soapy water can be used for a basic connection bubble test. Commercial gas leak detector solution is another option.
What do bubbles mean during a propane leak test?
Bubbles that grow, reform, or continue expanding can indicate that propane is escaping from the connection.
Can I use a lighter to find a propane leak?
No. Never use a flame, match, lighter, or other ignition source to test for a propane leak.
What should I do if the connection still leaks?
Close the propane cylinder valve, stop using the equipment, and contact your propane retailer or a qualified service technician.
More Propane Safety Guides

If you suspect an active leak, read what to do if you smell propane.

Learn how to transport propane tanks safely and how to store propane cylinders safely.

Need propane? Compare current local propane refill prices.

Safety notice: This article provides general consumer safety information. Always follow the propane cylinder and appliance manufacturer’s instructions. Do not attempt to repair or modify a propane cylinder yourself. If you suspect a significant propane leak or unsafe condition, move to a safe location and contact appropriate emergency services or a qualified propane professional.