Why Furnaces Are Red-Tagged, and What to Do about It

If a furnace is red-tagged, that means it’s unsafe to operate. A qualified professional (like one of our technicians or someone from the utility company) will apply the tag if they encounter unsafe operating conditions. Aside from applying the red tag, the technician will turn off the furnace and have the homeowner sign a document saying that they are aware it’s unsafe to operate.

Here are some common reasons why a furnace might be red-tagged:

Carbon Monoxide:

The most common reason why a furnace would be red tagged is due to a crack in the heat exchanger, which is the component that forces the flue gas out of the chimney or side wall. The heat exchanger becomes hot so that air blowing across it will warm up and flow into your home. If it cracks, there is the potential for carbon monoxide to enter the home.

Fire Hazards:

The second most common reason for a red tag would be due to problems with the burner tubes or gas valve. This is an unsafe condition relating to the flame on the furnace, which could pose a fire hazard.

Gas Leaks:

The gas company could red-tag a unit if it there is a leak in the gas pipe. In this case, they would turn off the gas to the home and require that a licensed plumber or HVAC company go to fix the gas leak.

What To Do

If the furnace in your home has been red-tagged, the first thing we recommend is that you obtain a second opinion. If Boulden Brothers has been the first to diagnose the issue, we will offer an internal second opinion so we can get another set of eyes on the situation. If you want to get a firsthand view, we have cameras that are designed to be operated in the heat exchanger. This technology allows us to see directly inside the furnace, which is something that many other service companies can’t provide. Homeowners can stand behind our technicians and see the small monitor that shows exactly what is going on.

We always make sure to put the homeowner’s best interest first, which means taking the time to perform a complete safety check of the system so we know they’re protected. If we do find a crack, there are two options: The heat exchanger can be replaced if it is under warranty. If the unit is out of warranty, that means that the components are all reasonably old. After one component has failed due to age, other components will probably start to fail as well. In this case, it’s usually a better option to replace the unit. It’s more likely for an older heat exchanger to experience a failure. It’s not a matter of if, but when—as the metal heats and cools, it will expand and contract, eventually leading to a breakdown.

If a homeowner would ever continue to operate a furnace after it has been red-tagged, they would put themselves and their entire family in danger. Cracks or out-of-whack components won’t fix themselves, so homeowners should take action by getting the issue addressed by a professional.

If your furnace has been red-tagged, get a hold of Boulden Brothers today by giving us a call or contact us online.