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What to Do When Your Gas Appliance Gets Red-Tagged
March 28, 2026 · 9 min read
Key Takeaways
- A red tag means a licensed technician found a safety hazard — it's a legal notification, not a sales tactic
- Type A red tags (immediate danger) shut off gas immediately. Type B tags allow continued use for a limited time
- Only a licensed G2 or G3 gas technician can issue or remove a red tag in Ontario
- You have the right to get a second opinion, but the tag cannot be removed without fixing the issue
Getting a red tag on your furnace, water heater, or boiler is stressful. It can feel like a technician just condemned your equipment — and sometimes the timing seems suspiciously aligned with a sales pitch. Here's what a red tag actually means, what your rights are, and how to handle it without overpaying or compromising safety.
What Is a Red Tag?
A red tag is an official TSSA (Technical Standards and Safety Authority) notification that a gas-fired appliance has a safety defect. In Ontario, any licensed gas technician (G2 or G3) who discovers a hazard during service, installation, or inspection is legally required to tag the appliance. It's not optional — a technician who sees a safety issue and doesn't tag it can lose their license.
The tag is a physical sticker placed on the appliance with the defect description, date, technician's name, and license number. A copy is filed with the TSSA.
Type A vs. Type B: The Critical Difference
Type A — Immediate Danger
The appliance is shut off immediately and the gas supply is disconnected. Type A conditions include:
- Gas leak detected
- Carbon monoxide levels exceed safe limits
- Cracked heat exchanger with active CO spillage
- Blocked or disconnected venting that allows combustion gases into living space
- Fire hazard from improper installation
You cannot use the appliance until the issue is repaired and a licensed technician clears the tag.
Type B — Repair Required
The appliance has a defect that doesn't pose immediate danger but must be repaired within a specified timeframe (typically 35 days). Examples:
- Inadequate clearance from combustible materials
- Missing or damaged vent connector
- Improper gas line sizing
- Non-functional safety device (e.g., pressure switch, rollout switch)
You can continue using the appliance during the repair window. If you don't fix it within the deadline, the gas utility can disconnect your gas supply.
Common Red Tag Scenarios
Cracked heat exchanger: The most common furnace red tag. A small crack may produce Type B (no immediate CO spillage). A large crack with measurable CO leaking into the air stream is Type A. Heat exchanger replacement costs $1,500–$3,000. If the furnace is over 15 years old, replacement is usually more cost-effective than repair.
Improper venting: Often discovered after renovations or DIY modifications. A vent pipe that terminates too close to a window, lacks proper slope, or uses unapproved materials gets tagged. The fix is usually $200–$600 in venting work.
Water heater issues: Water heaters get red-tagged for corroded vent connectors, missing drip legs, or failed relief valves. These are typically straightforward repairs.
Your Rights as a Homeowner
- Get a second opinion: You're not obligated to have the tagging company do the repair. Any licensed G2/G3 technician can assess and fix the issue
- Request documentation: Ask for the specific defect code and TSSA regulation being cited. A legitimate technician will provide this without hesitation
- Check the technician's license: Verify their G2 or G3 certification. You can look up TSSA license numbers online
- Dispute process: If you believe the tag was issued incorrectly, contact the TSSA directly. They can send an inspector to evaluate
Repair vs. Replace Decision
Use this framework when deciding:
- Equipment age under 10 years: Repair is usually worth it unless the defect is catastrophic
- Equipment age 10–15 years: Get repair and replacement quotes. If the repair is more than 50% of replacement cost, replace
- Equipment age over 15 years: Replace. A 15-year-old furnace or boiler is near end-of-life, and another component will likely fail within 2–3 years
How to Get the Tag Removed
Once the defect is repaired, a licensed gas technician must inspect the work, verify the issue is resolved, and submit a clearance to the TSSA. The red tag sticker is removed or marked as cleared. Only a licensed G2/G3 technician can clear a tag — you cannot self-certify.
Frequently Asked Questions
Can I remove a red tag myself?
No. Physically removing the tag doesn't clear the TSSA record. The defect remains on file. If you sell the home or have gas work done later, the unresolved tag will resurface. Only a licensed technician can legitimately clear it.
Do red tags affect home insurance?
Potentially. If a loss occurs related to a known, unresolved red tag, your insurer may deny the claim. Most policies require maintaining equipment in safe working condition. An unresolved red tag is documented evidence of a known hazard.
Are some companies using red tags as a sales tactic?
Legitimate red tags cite specific TSSA codes and are filed with the authority. If a technician says your system "should" be red-tagged but doesn't actually issue one, that's a sales pressure tactic, not a legal notification. Ask for the tag number and TSSA filing. If they can't provide it, get a second opinion.
Need a Second Opinion?
If your gas appliance has been red-tagged and you want an honest assessment of repair vs. replacement, book a free evaluation or call 1-855-539-4328. We'll tell you exactly what you need — nothing more.