Converting a Wood Fireplace to Gas in Toronto: Options, Costs and Rules (2026)

Here is the short version: in Ontario there are exactly two code-approved ways to convert a wood-burning fireplace to gas. A direct-vent gas insert turns the fireplace into a sealed, efficient heater and typically costs $3,000 to $6,500 installed in Toronto. A vented gas log set keeps the open fireplace look for often under $3,000, but it is an ambience product, not a heater. The vent-free kits that dominate American how-to articles are not permitted in Canada. This guide walks through both real options, the rules, and how to tell which one fits your fireplace.

Two real options in Ontario (and one that is not allowed)

Most of what ranks for this topic is written for American homeowners, and it usually lists three conversion routes: a gas insert, vented gas logs, or vent-free gas logs. In Canada the third option does not exist. Canada's natural gas installation code, CSA B149.1, which Ontario law adopts, does not permit unvented gas appliances. Any vent-free log set or conversion kit an online retailer is willing to ship you cannot be legally installed in a Toronto home, and no TSSA-certified technician will connect one. That leaves two genuine choices, and they solve different problems.

Option 1: a direct-vent gas insert

This is what most Toronto homeowners mean when they ask about converting to gas, and it is the option Natural Resources Canada describes plainly: "Inserts are used to convert existing wood-burning masonry or factory-built metal fireplaces to gas." A gas insert is a sealed gas fireplace sized to slide into your existing firebox. Trim panels close the gap between the insert and your masonry, and the result looks like a built-in gas fireplace living where the wood fire used to be.

The venting is the part that surprises people. Your chimney does not get reused as-is. NRCan's guidance is explicit that existing chimneys must be relined with an approved vent when a gas insert is installed. In practice the installer runs new continuous liner the full height of the chimney; direct-vent inserts use two, one drawing combustion air from outside and one carrying exhaust out. Because the firebox is sealed and breathes entirely through the liner, the insert does not pull warm air out of your living room the way an open fireplace does.

That is also why the heat is real. An open wood-burning fireplace is, in NRCan's words, extremely inefficient, and many actually cause a net heat loss from the home by drawing heated room air up the flue. When Canada tested gas fireplaces under its fireplace efficiency standard, weaker units scored around 30 percent while the better ones ranged from 50 to 70 percent. A modern direct-vent insert sits at the strong end of that picture and runs on a thermostat, so the room holds the temperature you set.

The inserts we stock and install run from 20,500 BTU (the Regency Gi25LE, sized for smaller fireboxes) up to 40,000 BTU (the Napoleon Oakville X4), with Regency's Liberty and Horizon lines, Napoleon's Oakville series, the Marquis Capri and the Majestic Ruby in between. Which one fits is mostly decided by your firebox dimensions, which is why the process starts with a tape measure rather than a brochure. Browse the gas insert lineup to see the range.

Option 2: a vented gas log set

A vented gas log set takes the opposite trade. Detailed ceramic logs sit on a burner inside your existing open firebox, so you keep the wide-open hearth look, and the flames are the most realistic of any gas product because they climb through the logs the way a real fire does. We carry RH Peterson Real Fyre sets in several styles.

The honest part: a vented log set is not a heater. The manufacturer's own installation instructions require the chimney damper to be fully open whenever it burns, and a damper clamp is installed so the damper can never fully close. Most of the heat goes up the chimney, exactly like a wood fire. What you are buying is the ritual of a fire at the press of a switch: no wood to haul, no sparks, no ash to shovel, no creosote building up. For a fireplace you light a few evenings a month for atmosphere, that can be the right purchase at the lowest cost of entry.

The rules in Ontario

Three rules shape every conversion in Toronto. First, gas work is licensed work: under Ontario Regulation 215/01, connecting and servicing gas appliances requires a TSSA-certified gas technician. Second, as the owner you carry a legal duty under Ontario Regulation 212/01 to keep any gas appliance maintained in a safe operating condition, which is one reason the work should be documented by a professional from day one. Third, the venting rules above: no unvented appliances, and a relined chimney for any insert.

One more step matters before anything gas-related happens: the chimney should be swept and inspected first. Years of wood burning leave creosote in the flue, and you do not want it sealed in behind a new liner or heated above an open log set. A conversion quote that skips the chimney assessment is a quote to be suspicious of.

What it costs in Toronto in 2026

A gas insert conversion typically lands between $3,000 and $6,500 installed. The spread comes from four things: the insert model itself, the liner run (a tall two-storey chimney costs more to reline than a bungalow's), the gas line (a short run from an existing basement line is cheap, a long run from the meter is not), and the trim or surround work. A vented log set usually comes in under $3,000 installed. If your fireplace or chimney is in rough shape and you are weighing a full tear-out instead, complete new gas fireplace installations run $4,500 to $10,000; our gas fireplace installation cost guide breaks down that math.

Running costs after the conversion are modest. At Toronto gas rates an insert burns roughly 15 to 35 cents per hour of gas at full output, depending on its size, several times cheaper per unit of heat than electric heating. The numbers are worked through in our gas vs electric comparison.

How the conversion actually goes

1. Measure and assess. We look at your firebox dimensions, the chimney's height and condition, and where gas can come from. Photos and a tape measure are enough to start the conversation.
2. Choose the insert or log set. The firebox opening decides which models physically fit; heat needs and style narrow it from there.
3. Sweep and inspect the chimney. Creosote comes out and the flue is checked before anything new goes in.
4. Install the liner and run the gas line. A TSSA-certified technician handles the gas connection; the liner is run the full height of the chimney for an insert.
5. Finish and commission. Trim panels close the opening, the unit is leak-tested and fired, and you get a walkthrough of the controls.

Once the chimney is prepped and the parts are on site, most insert installations are completed in a single day. After that, it is a gas appliance like any other: an annual service keeps it safe and keeps the warranty intact, and our gas fireplace maintenance guide covers exactly what that involves.

When conversion is not the right call

If your home has no gas service, or the run from the meter to the fireplace is long and awkward, the gas line can eat the budget; an electric fireplace may deliver the look you want with none of that cost. If the chimney needs major masonry repair, price that honestly before building a conversion on top of it. And if what you actually want is to keep burning wood but get real heat from it, a modern wood-burning insert does for wood what a gas insert does for gas: it turns an open fireplace into a controlled, efficient heater.

See both options burning

The fastest way to choose between an insert and a log set is to stand in front of both. Our Toronto showroom has live burning displays, and if you bring your firebox measurements and a few photos we can usually tell you on the spot what fits and what the installed price will look like. Call (416) 482-8585 or read about our installation service to see how the work is handled.

Sources

This guide draws on Natural Resources Canada's All About Gas Fireplaces guidance, Ontario Regulation 212/01 and Ontario Regulation 215/01 under the Technical Standards and Safety Act, the CSA B149.1 natural gas and propane installation code, and RH Peterson's Real Fyre vented burner installation instructions. Requirements vary with your specific fireplace and chimney; a site assessment settles what applies to yours.