When an HVAC technician puts a red warning tag on your furnace, it means they’ve decided it’s unsafe to use.
Red tags are no joke. It could have a gas leak, it might be a fire hazard, or it could be causing excess carbon monoxide in your home.
That said, not every red tag is justified. Even licensed gas technicians make mistakes, and in some cases, homeowners get pressured into expensive furnace repairs or a new furnace install they didn’t need.
If your furnace has been given a red tag, read through to the end before you make any decisions.
Table of Contents
Should I Get a Second Opinion on My Red Tag Furnace or Water Heater?
Yes, you absolutely should.
Some red flags are definitely legitimate and are there to keep your family safe.
Others have been issued prematurely or incorrectly in the past. Gas technicians can misinterpret readings, and fail to check parts thoroughly, and some unscrupulous ones even use red tags as a fear factor to get new sales.
If your furnace has been red-tagged, let us give you a FREE professional inspection and second opinion before you make any decisions.
We’ll thoroughly inspect your entire furnace and complete a combustion analysis to verify the efficiency and safety of the heat exchanger. The technician will actually show you the cracked or failed part inside the furnace, NOT a picture on their phone, and let you know if your red tag is legitimate and what your options are.
Book an inspection with us online or call us at 613-535-2720.
Why Red Tags are Important
First of all, you need to know what a red tag means.
A red tag is placed on a furnace that needs to be shut down because it’s a health hazard or could even kill you. According to the law (specifically CSA B149.1-10 Natural Gas and Propane Installation Code), a technician is obligated to shut down furnaces that could injure or kill the people in the home.
What’s the concern? These furnaces often have one or more problems that can cause dangerous combustion gases, in particular carbon monoxide (CO), to escape into your home.
CO is colourless and odourless, and it’s a natural byproduct when anything burns. Normally, it escapes harmlessly up the exhaust vent. But it’s deadly if it leaks into your home – it’s also the same gas that makes it dangerous to start your car with the garage door closed. Because it makes people disoriented and “sleepy,” entire families have been killed by CO without even knowing it. Tragically, it happens almost every year.
If the choice is between causing problems and expenses versus saving lives, the technician must choose to save lives; the technician is required as per the gas code, and their license is on the line.
Why Fake a Red Tag?
The Red Tag rule is supposed to save lives, but clearly, some companies are abusing it by making false claims. Here’s how the scenario often works:
- A technician says a furnace is dangerous and needs to be shut down until it’s repaired or replaced.
- Instead of a low-cost maintenance check or medium-cost repair, you end up having to replace the entire furnace, and the crooked company makes a lot more money. It’s winter, and it’s freezing, and you worry about frozen plumbing, so that adds a sense of urgency to the scenario.
Often the problem cited by the technician is a “cracked heat exchanger” – which is expensive to replace, even when under warranty. If the furnace is more than 15 years old, it often makes more sense just to get a new one.
Types of Red Tags
Not all red tags have the same level of urgency.
There are two types of red tags:
Type A Red Tag: Immediate Hazard
A Type A red tag means your furnace is in immediate danger and shouldn’t be turned back on. Your gas provider will turn off your gas supply, and you won’t be able to use your furnace until it’s repaired or replaced.
Some common reasons why you might get a Type A red tag:
- A cracked heat exchanger
- A gas leak
- Severe carbon monoxide leak detected
- Safety controls not working correctly
- Ventilation system clogged or broken
Type B Red Tag: Time-Sensitive Issue
A Type B red tag is less urgent but still serious. It means your furnace has a safety issue that needs to be fixed, usually within 30 days. If you don’t get it fixed within the time given, your gas provider will probably shut off your service.
Some reasons why you might get a Type B red tag:
- An older, rusty heat exchanger
- Something wasn’t installed correctly
- The furnace isn’t burning fuel efficiently usually because of improper gas pressure, dirty burners, or poor airflow
- Aging gas lines
- Problems with the electrical system
Can Red Tags Be False Alarms?
Unfortunately, yes. While many red tags are legitimate, some are issued unnecessarily, whether on purpose or not. For example:
- A furnace with a new heat exchanger was red-tagged based only on its serial number.
- Some licensed gas technicians red-tag equipment without fully checking for cracks or malfunctions.
- Combustion readings can be misinterpreted.
- Other technicians will try to create fear in clients by drumming up furnace sales and repair charges.
What Should You Do If Your Furnace Is Red-Tagged?
If your furnace gets red-tagged, stay safe, ask for proof, and get a second opinion.
Follow these steps:
- Shut it down. Safety should always come first.
- Check if your certified gas technician followed all assessment steps. Ask for a detailed explanation and proof of the issue. Get them to show you the crack or failed component in the furnace – NOT from their phone or the combustion readings they measured that warrant a red tag.
- Find temporary heat for your home. If a replacement is needed, some companies offer electric heaters while you wait. ATEL has dozens of electric space heaters and extension cords ready for emergency use to help until the furnace is working again.
- Get a second opinion from a licensed and certified gas technician. ATEL Air provides free second opinions with no dispatch fee.
How Do Technicians Test for Dangerous Cracks in Heat Exchangers?
Cracked heat exchangers do happen, and when they do, it’s serious. Here’s how we check to see if there’s a problem.
Our first clue that there may be issues with a heat exchanger is observing the flame pattern in the furnace. It can start to “dance” and move around once the indoor blower comes on. We can sometimes find the problem with an electronic combustion analyzer – the oxygen level will change as the blower comes on and forces air into the heat exchanger through the crack.
When we suspect a problem, the next step is to confirm the location. Cracks can often be seen with the naked eye – once you find the location.
Sometimes, this is as easy as opening an inspection port into the ductwork just above the furnace and looking into the top of the furnace with a flashlight. Sometimes, we must use a dye and a black light to confirm a small leak – this is because cracks expand when heated. On occasion, we must remove the exchanger right out of the furnace to pinpoint the crack or leak.
Some are small, and some are huge, as you may see in the photos. The larger cracks and leaks are heat exchangers that have been running for longer periods of time without regular maintenance and inspection.
Some examples of holes and cracks we’ve seen in heat exchangers. On the far left, the hole is very large, because the furnace has run for a couple years without regular inspections and monthly filter changes.
The middle two images show fine cracks. The furnace on the far right has been corroded by combustion gasses. This corrosion has caused the inside white lining to flake off and block the flue gases-shutting down the flow of the flue gases which then shuts down the furnace and NO HEAT!
Red-Tagged Furnace? Get a Free Second Opinion
At ATEL Air, we believe in fair and honest service. We also know HVAC and gas technicians can rush jobs and sometimes make mistakes.
If your furnace has been red-tagged, don’t rush into a costly repair or buying a replacement without first getting a second opinion.
We are licensed and certified to provide free second opinions (with no dispatch fee) on red-tagged furnaces. You deserve to know the truth before making such a big decision.
Call us today at 613-535-2720 to schedule your free assessment or book one online!