Plumbing Smoke Test: What is it and how does it work? | Terrys Plumbing

Plumbing Smoke Test: What is it and how does it work?

One of the worst experiences you can have is coming home to an unknown, foul-smelling odor. What’s even more frustrating is trying to locate the source of it.  If you suspect it may be coming from your sewage line or piping, finding the source is almost impossible. This is where smoke testing services begin to shine. In this blog, we go over what a plumbing smoke test is and how it works to your benefit.

Why Smoke Testing?

The truth is, smoke testing is poorly named, as no smoke is actually used in the process. What is used is more like fog than smoke–similar to a fog machine used for Halloween or parties. This specialized machine, called a blower, puts out a colored, odorless fog that makes locating breaks and leaks easier.

How does a Smoke Test Work?

Since odors are invisible to the eye, it’s difficult to find a sewer gas leak. Smoke testing solves this problem. They work by injecting a colored fog into the line in question. Once the line is full, the fog will help show plumbing professionals where the leak is coming from. Fog may also be seen coming out of the ground, manholes, or vents on homes and businesses. Depending on where the fog is seen, it may indicate a break or other defect in the sewer line which allows the fog to escape. However, if the leak is still too small to see, the fog leaves behind a non-toxic UV residue. This residue when illuminated by a black light will help guide plumbers to the source of the leak.

Any system that is “sealed” can be tested with smoke testing. So, if you would like to test a septic tank, water tank, or even an HVAC system for leaks, smoke testing can be an effective way to ensure none of your systems are leaking or causing further damage to your property.

Damage Caused by Untreated Leaks

Gas leaks have the potential to cause more damage than you may think. Injuries can occur either as a result of exposure or ignition. Some injuries you may receive or symptoms you may notice are as follows:


  •       Burns
  •       Fractured bones
  •       Neurological issues
  •       Cuts & Scrapes


  •       Headaches
  •       Nausea
  •       Dizziness

Preparations Required

While the actual process of smoke testing doesn’t require any preparation, it’s important to let neighboring businesses or homes know when smoke testing is going to occur. This is because multiple properties tend to share the same sewage line, and the issue may be located on someone else’s property.

Contact Super Terry today!

If you have leaky pipes give us a call. Our plumbers are always standing by to help you find and repair troublesome leaks.