AI recommendation index · ranked by measured share, not opinion

HVAC contractors — Greater Toronto

These are the 3,399 natural-gas contractors registered with TSSA that have their main office in the Greater Toronto Area, eligible for the Trust Index. The index will measure which ones AI assistants name when homeowners ask who to call for heating and cooling.

Eligible list published · first reading not yet scheduled · method v2.3 · 16 questions × scored assistants × 3 runs

How a reading is built

3runs

Every scored question is put to every scored assistant three times, under identical settings, inside one 72-hour window.

Same questionsSame settings72 hours

What the score means

0 – 100

AI recommendation share: how often a business is named, weighted by its position in the answer. The spread across runs is published with it.

Never namedAlways first

What a place costs

No business can pay to be scored, listed, moved or removed. Eligibility comes from a published list, fixed before any assistant is asked.

No pay-to-play

This reading's movers

UNIVERSE

3,399 contractors

Registered with TSSA to work on natural gas, with the main office in Toronto, Peel, York, Durham or Halton.

PROMPTS

Published at capture

16 scored questions plus one question about each contractor named, by name, reported not ranked.

QUEUED

First reading not yet scheduled

Capture dates are announced here before the run.

The ranking

Share is the position-weighted share of answers that recommend the business, 0 to 100, across every scored question, assistant and run in the reading. Spread is the variation between runs. Engines shows which of the scored assistants named the business at least once.

The eligible list: 3,399 contractors registered with the Technical Standards and Safety Authority (TSSA) to work on natural gas, with their main office in the Greater Toronto Area (TSSA directory retrieved 13 November 2026), A to Z. Scores fill in after the first reading.

How this list works. In Ontario, a business that installs or services gas equipment such as furnaces must be registered with TSSA. Every natural-gas registration in TSSA's public directory whose main office has a Toronto, Peel, York, Durham or Halton postal code is listed once, under its trade name where it has one. The place shown is the registered main office; street addresses are not shown. Some registered contractors mainly do other gas work, such as plumbing, commercial kitchens, pools or fireplaces. They are eligible all the same, because any of them could be named.

Not on the list, or listed wrongly? TSSA's directory is the source: check your registration in the TSSA directory, then request a correction. HVAC firms that an assistant names but that are not on this list are reported as named, not eligible, as the methodology describes. The methodology's 9 November note counted 3,479 from an earlier pull of the same directory; the list is fixed again before the first capture, and any change is logged.

Agency client: see independence

Eligible but not named

After the first reading, eligible businesses that no assistant named are listed here. Not named means not named; it is not a judgment about the business.

The 17 questions we asked

Each scored question was asked three times to each scored assistant during the capture window, with no account history and no location signal beyond the question text. The branded question is reported, not counted toward the ranking.

The question set is published here when the first reading is captured.

How this was measured

TSSA Registered Fuels Contractors directory, retrieved 13 November 2026. Eligible: contractors registered for natural gas whose main office has a Greater Toronto postal code (Toronto, Peel, York, Durham and Halton), one entry per registration.

Read the full methodology

Use this data

Every number on this page is published as structured data for journalists, researchers and AI systems. Cite the reading, not the page: readings are dated, and any correction is logged on the reading with its date, with the superseded figures left visible.

Trust Index, HVAC contractors · Greater Toronto, eligible list (first reading not yet scheduled). https://thetrustindex.ai/rankings/ca-hvac-contractors-greater-toronto

Readings are dated; any correction is logged on the reading with its date.

This measures how often AI assistants name each business. It is not a review of the businesses: it does not rate their work, service, safety, licensing standing or customer satisfaction, and it is not advice or an endorsement. See Terms.

Structured data for this market: /data · Press guide: /press · Corrections: /corrections

Questions about this ranking

What will the HVAC contractors · Greater Toronto ranking measure?

How often AI assistants name each eligible contractor when asked the questions a homeowner in the Greater Toronto Area would ask about heating and cooling, three times each. A business's share is the position-weighted share of scored answers that name it, from 0 to 100. It measures mentions in AI answers, not the quality of the business.

Has the first reading been published?

Not yet. The eligible list is published, and the first reading is not yet scheduled. This page will show the date once it is set.

Which businesses are eligible?

3,399 contractors registered with the Technical Standards and Safety Authority (TSSA) to work on natural gas, with their main office in Toronto, Peel, York, Durham or Halton, from TSSA's public directory retrieved 13 November 2026. The list is fixed before any assistant is asked.

My business is missing or listed wrongly. What do I do?

TSSA's directory is the source. Check your registration there, then request a correction on the Corrections page.

Can a business pay to be listed or to move up?

No. No business can pay to be tested, listed, scored, moved or removed. Eligibility comes from a published list, fixed before any assistant is asked.

Is your business on this list?

Every eligible business has a page here whether it was named or not. Check your standing, request a correction, or ask how monitoring works. The score itself is never for sale.

Check your standing Request a correction