Protect safety, code compliance, and system performance

A small gas-fitting mistake can become a major safety and legal problem. In Ontario, anyone doing regulated gas work must hold a TSSA Certificate of Qualification. Municipal permits and inspections are normally required for new lines, major alterations, or appliance replacements. See your local rules on Ontario building permits.

This checklist shows exactly what to verify before you hire a gas fitter. You'll learn how to confirm credentials and demand proper pressure and leak testing. You'll also learn how to check documentation and permits and evaluate emergency response coverage. It's written for Niagara homeowners and property managers who need safe, code-compliant work and reliable 24/7 service.

Confirm TSSA certification and that the contractor is registered

Worried the person working on your gas lines might not be qualified? You should be. Gas work in Ontario is tightly regulated to protect safety and property.

Ontario requires anyone doing regulated gas work to hold a TSSA Certificate of Qualification. This rule covers installations, repairs, activations, and major alterations.

There are three certification levels. G3 is entry level and works under supervision. G2 works independently on appliances up to 400,000 BTUh. G1 can work on all gas-fired equipment and supervise others.

Quick verification checklist

1. Ask the technician for their full name and Certificate of Qualification number, and ask to see their certification card.
2. Look that number up using the TSSA public tools so you can confirm the certificate level and current status. TSSA Registered Fuels Contractor lookup
3. Confirm the company is a TSSA-registered fuels contractor and that the technician is employed by that contractor. Ontario law requires both individual certification and contractor registration for fuel-related work.
4. Ask whether the tech’s certification level covers your specific equipment, such as a boiler, tankless water heater, or hybrid heat-pump backup. Also ask who will sign permits and handle inspections.
5. Request written confirmation of warranties and whether the installer’s labor warranty is separate from the manufacturer’s product warranty. Keep this documentation to protect your coverage and compliance.

Why these checks matter: they reduce safety risk and keep your permits and warranties valid. A verified technician and registered contractor also show the company follows provincial standards.

We recommend walking away from anyone who refuses to provide a certificate number or who cannot be found in the TSSA lookup. If you want a quick primer on what to do before a certified fitter arrives in an emergency, see our emergency HVAC tips for homeowners.

What must be tested on-site and the paperwork you should get

Want to know the nonnegotiables before a gas fitter leaves your home? Insist on specific safety tests, hardware, and clear paperwork.

In Ontario, permits and inspections are normally required for new lines, major alterations, or appliance replacements. Contractors typically obtain permits and arrange rough‑in and final inspections through your local building authority. Ontario building permits

Essential on-site tests every certified fitter must perform

• Perform a pipe tightness or pressure test and verify there is no measurable pressure drop over the required period.
• Check joints and connections using calibrated electronic leak detectors or a soapy-water solution to find any escaping gas.
• Run combustion analysis and flue spillage checks on furnaces, boilers, and water heaters to confirm safe operation and CO limits.
• Document all test results and issue a compliance record or certificate before leaving the site.

Required safety hardware and materials to verify

• Make sure accessible manual shutoff valves are installed near each appliance.
• Confirm a sediment trap is fitted where required at appliance connections.
• Verify approved piping materials were used, like black steel or CSST, and that CSST is properly bonded and grounded.

Paperwork you must receive and simple homeowner steps

• Get permits and inspection records or a formal compliance certificate as proof the job passed local checks.
• Ask for installation records showing pressure readings and combustion test results tied to the date and technician.
• Collect manufacturer manuals, warranty registration details, and a maintenance log for future service and resale value.

Before the visit, clear work access and have appliance model numbers and previous paperwork ready. After the job, keep all documents in a safe place for warranties, insurance, or future inspections. Emergency HVAC tips for homeowners

If a fitter refuses these tests or will not provide documented results and permits, walk away and get a second opinion.

What to Ask, What to Watch For, and How to Compare Bids

Not sure which estimate is a safe, fair choice? Start by treating the first call like a screening interview. Verify credentials and insurance before you book an on-site visit.

We recommend a short, prioritized question list for both phone and on-site estimates. The answers will reveal whether a fitter follows code, carries insurance, and plans proper testing.

Priority questions for phone and on-site estimates

• Can you give your full name, company name, and TSSA Certificate of Qualification number?
• Do you have current general liability and WSIB/workers’ compensation coverage, and can you provide proof?
• Who pulls permits and books inspections: you or the homeowner?
• What exactly is included in the scope of work, and can you itemize labour versus materials in writing?
• Which manufacturer models and part numbers do you plan to use, and will installation follow manufacturer requirements?
• What safety tests will you perform on-site, and will you provide documented results and compliance certificates?
• What is the projected timeline, and how do you handle unexpected issues or delays?
• What warranties do you offer for labour, and how does that differ from the equipment manufacturer warranty?

Ask for a written estimate that lists model numbers, test protocols, permit responsibility, and warranty details. If a fitter hesitates to put this in writing, consider that a warning sign.

Red flags that mean walk away

• Refuses to show credentials or give a Certificate number.
• Insists on skipping permits or asks you to sign off for unpermitted work.
• Cannot provide proof of insurance or WSIB coverage.
• Demands cash-only payment or offers no written estimate.
• Gives a very low quote but provides vague scope or no testing plan.

These are established warning signs that work may be unsafe or noncompliant. The Technical Standards and Safety Authority flags the same issues as serious risks.

Quick apples-to-apples bid checklist

• Scope of work: confirm exact tasks, pipe changes, and disposal of old equipment.
• Materials and equipment: list exact manufacturer model numbers and efficiency ratings.
• Safety tests: require pressure and leak tests, combustion analysis, and written results.
• Timeline and permits: get start and finish dates and who is responsible for permits and inspections.
• Warranties and documentation: separate equipment warranties from the fitter’s labour warranty, and ask what keeps the manufacturer warranty valid.
• Post-install support: ask about emergency response, required maintenance, and provision of installation records and serial numbers.

Manufacturer warranties often require professional, code-compliant installation. Natural Resources Canada explains improper or unlicensed installs can void coverage.

For help comparing contract language and service-level terms, see our practical guide to commercial HVAC contracts. Commercial HVAC contracts: what Niagara businesses should require

Confirm system-specific competence and realistic 24/7 response times

Worried the fitter actually knows your boiler, tankless water heater, or hybrid heat-pump backup? Ask directly about brand and model experience and whether they perform formal load calculations.

For tankless units, a technician must verify the gas distribution capacity so multiple appliances won't starve the system. For ductless heat pumps with gas backup, ask how they integrate controls so the system switches cleanly between fuels.

• Ask for recent job examples with the same brand or model and for contactable references from Niagara customers.
• Require a formal load calculation and, for forced-air systems, an inspection of ducts for leaks or sizing problems.
• Demand documented safety testing after work, including pressure/leak tests and combustion analysis, with results on file.
• If you manage commercial property, require a G1-certified technician and that the company is a TSSA-registered fuels contractor.
• Ask for a preventative maintenance plan, a detailed service history, and proof of WSIB and liability insurance to reduce downtime risk.
• Verify who pulls permits, who signs inspections, and whether the contractor uses advanced diagnostics to catch problems before they fail.

If you smell gas evacuate immediately on foot and do not operate switches or phones near the leak. Once safe, call 911 and the gas utility from a safe location, then contact a certified gas fitter after the scene is declared safe.

Expect 24/7 contractors to aim for arrival times of one to three hours for urgent calls. Some firms keep emergency units that can be en route within 45 to 90 minutes for critical failures. Ask the company to explain their SLA tiers and response guarantees so you know what service level you will get. See our guide to emergency SLA tiers for businesses

Your quick decision framework

Hiring a gas fitter is about safety, compliance, and long-term value. Use this short framework when you compare bids or schedule work.

• Verify the technician’s TSSA Certificate of Qualification and confirm the company is a TSSA-registered fuels contractor.
• Require permits, pressure and leak tests, combustion analysis, and written compliance records before the fitter leaves.
• Ask targeted estimate questions and get an itemized scope that lists materials, timelines, and who pulls permits.
• Prioritize documented experience with your system type and dependable 24/7 emergency coverage so you aren’t left without service.

When safety and warranties matter, choose a certified fitter you can verify and trust. If you need certified gas fitting in Port Colborne or elsewhere in Niagara, Thermal Comfort Solutions can help. Call us at 289-696-4440. We’re available 24/7 for emergency support.