Discovering a red tag on your furnace can be alarming. A technician came to service your unit, and instead of a clean bill of health, you got a tag and a shut-off notice. What happens now?
Red tags in Ontario are issued under TSSA (Technical Standards and Safety Authority) regulations when a gas appliance is found to be unsafe or non-compliant. They're a formal legal notice — not just a technician's opinion.
Type A Red Tag vs. Type B Red Tag
There are two types of red tags in Ontario, and they have very different consequences:
The appliance presents an immediate danger to life or property. The gas supply is disconnected on the spot by the technician. The appliance cannot be turned back on until the issue is corrected and a licensed technician removes the tag. Common causes: carbon monoxide leak, cracked heat exchanger, gas leak, no venting.
The appliance has a safety deficiency but is not an immediate danger. It can continue to operate temporarily, but the issue must be corrected within a specified time (usually 30 days). Common causes: improper venting, missing clearances, code violations on older installations.
What Triggers a Red Tag?
- Cracked heat exchanger (carbon monoxide risk)
- Gas leaks or damaged gas lines
- Inadequate or blocked venting / flue
- Missing or non-functional pressure relief valve
- Improper combustion air supply
- Equipment installed without a permit
- Non-compliant clearances around the appliance
- Damaged or corroded components presenting a hazard
Who Can Issue a Red Tag?
In Ontario, only TSSA-registered gas technicians (G1 or G2 licensed gas fitters) can issue red tags on gas appliances. Your utility company (Enbridge) can also flag issues when they come for meter work. The tag is backed by TSSA authority — ignoring it is not a legal option.
Can You Remove a Red Tag Yourself?
What to Do After Getting a Red Tag
- Don't panic — but do take it seriously. Especially for Type A tags, treat it as a genuine safety issue.
- Read the tag — it will specify the exact violation and the time you have to correct it.
- Get a second opinion on the repair cost if the quote seems high. The technician who issued the tag is allowed to quote repairs, but you're not obligated to use them.
- Decide: repair or replace. If the furnace is 15+ years old or if a cracked heat exchanger is the cause, replacement is often the right financial call.
- Have the repair verified by a licensed technician who can remove the tag and confirm compliance.
Red Tags and Home Sales
A red tag that comes up during a home inspection can kill a sale or significantly affect the price. As a seller, it's better to address it proactively before listing. As a buyer, a red tag means the issue must be resolved before closing — factor the repair cost into your negotiations.
The Bottom Line
A red tag isn't a scam or a scare tactic — it's Ontario's safety system doing its job. Most red tags are legitimate, and most of the issues causing them are real hazards. Treat it seriously, get quotes, and make a clear-eyed decision about repair vs. replacement.
If you've received a red tag or want a second opinion on a repair quote, Alderwood Mechanical can help. We're G1 licensed gas fitters serving Toronto and the GTA. Call 437-229-8618 — we can usually come the same day.
Alderwood Mechanical serves Toronto, North York, Scarborough, Etobicoke, Mississauga, Vaughan, Markham, Oakville, and surrounding GTA. G1 licensed gas fitters. No contracts. Upfront pricing.