What's the price to convert my older fireplace to a sealed combustion direct vent system in Ottawa?

Converting an older open masonry fireplace to a sealed combustion direct-vent system in Ottawa typically costs $3,000 to $7,000 installed, depending on whether you're installing a gas insert into the existing firebox or removing the old fireplace entirely and building a new installation from scratch.

Understanding Your Conversion Options

The most common and cost-effective approach is installing a direct-vent gas fireplace insert into your existing masonry firebox. This option runs $2,500 to $5,500 installed and preserves the aesthetic appeal of your original fireplace while converting it to a sealed, efficient heating appliance. The insert sits inside the existing opening, and a stainless steel double-wall vent pipe is run through the chimney or through the exterior wall to the outside. This is a much faster project than full removal and rebuilding.

If your existing chimney is severely deteriorated, blocked, or cannot safely accommodate a vent pipe — a common situation in Ottawa given our brutal freeze-thaw cycles — you may need to abandon the old firebox entirely and install a new direct-vent gas fireplace against the same wall or in a new location. This full conversion runs $5,000 to $7,500 installed and includes demolition of the old fireplace, new gas line installation, framing for the new unit, drywall, finishing, and the complete venting system.

Why This Matters in Ottawa's Climate

Open masonry fireplaces lose 85 to 90 percent of their heat straight up the chimney — you are essentially paying to heat the outdoors. A sealed direct-vent system recovers 70 to 85 percent of the heat from combustion, meaning you actually get warm air into your living space rather than watching it escape. In Ottawa winters that regularly hit -25 to -30 degrees Celsius, this efficiency difference translates to real dollars saved on heating over the life of the appliance.

The conversion also addresses one of Ottawa's most persistent fireplace problems: water infiltration through the chimney crown and mortar joints. An older masonry chimney that has been exposed to decades of our freeze-thaw cycles often has cracks and deteriorated mortar that allow water into the structure. When you seal that chimney off and eliminate the draft, you stop water from being drawn through the chimney interior, which prevents further damage and eliminates the risk of water leaking into your walls or basement during heavy rains and spring melt.

What's Actually Included in the Cost

The $2,500 to $5,500 insert price includes the gas insert unit itself, installation labour, the direct-vent termination kit (the elbows and cap that go through your wall or up through the chimney), hearth protection if needed, gas line connection, and a TSSA compliance tag from a licensed gas fitter. Some contractors include a basic surround trim package; others charge $300 to $800 extra for finish trim around the insert opening.

The $5,000 to $7,500 full conversion price adds demolition of the old fireplace, removal of damaged masonry if necessary, new framing studs, drywall installation and taping, paint or finishing to match your wall, a new gas line run from your main or existing line, proper venting termination, hearth pad installation, and all labour. If you want a stone or tile surround to match the aesthetic of the original fireplace, add $2,000 to $4,000 more.

Important Considerations

TSSA licensing is non-negotiable. Any gas work — including running the gas line and connecting the insert — must be performed by a TSSA-licensed gas fitter (G2 or G3 certificate). After installation, the insert must be tagged with a TSSA compliance label. If your home insurance company discovers unlicensed gas work, your policy can be cancelled. Unlicensed gas work is also illegal in Ontario.

Your existing chimney's condition matters enormously. If your chimney is sound and can accommodate a vent pipe through its interior, the insert option is straightforward. If the chimney has extensive spalling, a severely deteriorated cap, or is blocked with debris or soot buildup, a WETT-certified chimney professional needs to inspect it before you commit to an insert. You may discover the chimney needs relining ($2,000 to $5,000) before venting through it is safe — in that case, venting through the exterior wall becomes the better option.

Timing matters in Ottawa. Schedule this work for spring (April through May) or early fall (September through October). Gas line work and TSSA inspection can happen any time, but if exterior venting work is required, the outdoor portion should be completed before deep winter arrives.

Permits and inspections are required. The City of Ottawa requires a building permit for fireplace removal and new installations. After the work is complete, a TSSA inspection is mandatory for any gas appliance, and you should request a Level 1 WETT inspection for insurance purposes — typically $250 to $450 — to document that the entire system (including clearances to combustibles and hearth protection) meets code.

When you're ready to get quotes, ask each contractor whether they are TSSA-licensed, whether their price includes the TSSA compliance tag, and whether they handle the building permit application or if you need to apply yourself. You can browse fireplace conversion specialists through the Ottawa Construction Network directory at justynrookcontracting.com/directory to compare local contractors and view their experience with direct-vent conversions in the Ottawa area.

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Looking for experienced contractors? The Ottawa Construction Network connects Ottawa homeowners with qualified professionals:

• Justyn Rook Contracting
• RenoMotion Inc.
• Best Hand2Hand moving company
• SDR Electric, Plumbing & Heating Inc.
• Leeds Property Maintenance