The One Question to Ask Every HVAC Contractor Before You Let Them In

Most Ontario homeowners never think to ask whether the person working on their furnace or water heater is actually licensed to do so. They assume that if someone shows up with a van and tools, they must be qualified. Unfortunately, that assumption is wrong — and it can cost you thousands.

What Is TSSA and Why Does It Matter?

TSSA stands for Technical Standards and Safety Authority. In Ontario, any technician who works on natural gas appliances — including furnaces, water heaters, and boilers — is legally required to hold a valid TSSA license. This isn't optional. It's the law.

An unlicensed technician working on your gas appliances can:

• Void your equipment manufacturer warranty
• Void your home insurance policy
• Create gas leak or carbon monoxide risks
• Result in fines for both the technician and the homeowner
• Lead to a red tag — meaning your gas gets shut off

How to Verify a TSSA License in Ontario

1. Go to tssa.org
2. Click on "License Lookup" or "Verify a License"
3. Enter the technician's name or license number
4. Confirm the license is active and covers the type of work being done

What Types of TSSA Licenses Exist?

• G1 — Can work on all gas appliances including high-pressure systems
• G2 — Can work on residential gas appliances (furnaces, water heaters, stoves)
• G3 — Limited to specific appliances only

For furnace and water heater installation, you want a technician with at minimum a G2 license.

Red Flags That Suggest an Unlicensed Technician

• Refuses or hesitates to provide a license number
• Found on Kijiji or Facebook Marketplace with no business registration
• Offers prices significantly below all other quotes
• Cannot provide a written quote or invoice
• Pays cash only with no receipt
• Has no verifiable Google reviews or business address

GT Home Services Is TSSA-Registered

GT Home Services is TSSA-registered (#000307842), and our gas work is done by a TSSA G2-certified gas technician. We've been installing furnaces, water heaters, and HVAC systems across Ontario since 2017 with a 4.8-star rating and 140+ verified Google reviews. You can verify our credentials before we arrive.

We Serve All of Ontario

GT Home Services is TSSA-registered and provides HVAC installation across Ontario, including: