What to do if you get a red tag on your gas appliance

Short answer: A red tag is a written safety notice a licensed gas technician (TSSA G1, G2, or G3) leaves on an appliance when they find a hazard that keeps it from being safely used as-is. Ontario has two levels: Type A (immediate hazard) — the gas supply is shut off and locked at once, and Type B (non-immediate hazard) — you have a defined window (typically 30–90 days) to correct the fault. Never remove the tag yourself, never turn the gas back on, and call a licensed technician to correct the fault and re-inspect.

What is a red tag?

In Ontario, only a licensed gas technician certified through the Technical Standards & Safety Authority (TSSA) can service, inspect, or condemn a natural-gas or propane appliance. When a technician finds a defect serious enough that the appliance cannot be safely operated as-is, they physically attach a bright red tag to it and file a report with TSSA. The tag records what was found, what class of hazard it is, and what has to happen before the appliance can be legally used again.

Common triggers for a red tag include: a cracked heat exchanger, elevated carbon-monoxide readings, a compromised or blocked vent, a gas leak, corrosion inside the burner, a failed pressure test, missing combustion air, or a component that no longer meets code.

The two types of red tag in Ontario

Type A — Immediate hazard (gas is shut off immediately)

The technician has judged the appliance to be an immediate risk to your household, think confirmed gas leak, CO in the living space, or a cracked heat exchanger venting combustion gases into the airstream. The technician will:

• Shut off the gas supply at the appliance shut-off valve and lock or seal it.
• Attach the red tag.
• Notify Enbridge Gas / your utility, who will normally lock or remove the meter.
• File a Type A report with TSSA within 24 hours.

You cannot legally operate the appliance until a licensed technician has corrected the defect, inspected the repair, and cleared the tag with TSSA/the utility.

Type B — Non-immediate hazard (defined correction window)

The appliance has a serious defect but is not judged to be an immediate danger, for example, a marginal draft on the vent, a component operating outside spec, or missing safety-shutoff functionality. The technician will:

• Attach the red tag documenting the defect.
• Give you a written correction window — usually 30, 60, or 90 days — to have a licensed technician correct the fault and re-inspect.
• File a Type B report with TSSA.

If the fault is not corrected within the window, it is treated as a Type A and the gas can be shut off.

What you should do next (step-by-step)

1. Do not use the appliance. Even for a Type B, running an appliance with a documented safety defect can escalate the situation and create liability if a claim is filed later.
2. Do not remove the red tag. Removing or defacing a red tag is a violation of the Ontario Technical Standards and Safety Act. Only a licensed gas technician can clear it after a compliant repair and re-inspection.
3. Read the tag carefully. The tag documents what defect was found and what has to happen next. Take a photo of the front and back for your records, you'll need it for the follow-up quote and any insurance conversation.
4. Book a licensed TSSA-certified technician. A G1 (any commercial or residential appliance up to 400,000 BTU/hr), G2 (up to 400,000 BTU/hr with specific limitations), or G3 (residential gas fitter within scope) can inspect, quote, and correct the fault. Ask for their TSSA registration number.
5. Correct the defect, then have it re-inspected. Once the repair or replacement is complete, the technician re-tests the appliance, confirms it meets code, removes the tag, and files the closure report with TSSA. Only then is the appliance legally back in service.
6. Keep the paperwork. Retain the original red tag, the technician's work order, and the closure report for at least the life of the appliance. It matters for warranty, insurance, and resale.

The common misconception: "I'll just switch it back on for one cold night"

The single biggest mistake we see homeowners make is quietly turning the gas back on to get through a cold snap. A red tag exists because a certified technician judged the equipment unsafe, usually because the risk is combustion venting into the home, which is silent and deadly. If a Type A is subsequently linked to a CO incident or house fire, your home insurance policy can be voided for operating the appliance in violation of the tag. It's not worth it. If the outage falls in heating season, contact us: we run 24-hour emergency dispatch across the GTA and can prioritize an emergency repair or a same-day rental heater.

How Energy Clean handles a red tag call

When a homeowner calls us with a red-tagged furnace, boiler, or water heater, our workflow is:

1. Priority dispatch: Type A situations get same-day attention.
2. A TSSA-certified technician arrives, inspects the tag, and diagnoses the failure independently, never taking the previous technician's word alone.
3. You receive a written quote for both a repair (where possible) and a code-compliant replacement, with real repair-or-replace math, not a sales script.
4. Once you approve, the fix is performed, the appliance is re-tested (including CO in the airstream, draft on the vent, and gas-tightness on all fittings), and the tag is cleared with TSSA.
5. All paperwork — corrected inspection, warranty registration, TSSA closure — is filed for you.

Not sure a red tag was warranted? Get a free second opinion; we quote a lot of red-tag second opinions and honestly tell homeowners when the previous call was correct.

Related emergency guidance

A red tag is a documented hazard. An active hazard — natural gas smell, hissing at the meter, or a carbon-monoxide alarm sounding — is handled differently and immediately. Read what to do if you smell gas or your CO alarm sounds and keep Enbridge's 24-hour emergency line (1-866-763-5427) somewhere your family can find it.