# Boiler Replacement Toronto | End-of-Life Gas Swap URL: https://boilerinstallationtoronto.ca/boiler-replacement-toronto/ Toronto Boiler Installation [/ →](/) # Boiler Replacement in Toronto: End-of-Life Gas Boiler Swaps, Cast Iron Conversions and High-Efficiency Retrofits Across the GTA Last updated: September 19, 2026 End-of-life gas boiler replacement for 15 to 40 year old systems, including cast iron conversions, chimney liner de-commissioning, gas line sizing, and disposal across Toronto and the GTA. Published band $8,500 - $14,500 CAD older Toronto cast iron retrofit (CAD) Call (647) 254-9788 [tel:+16472549788 →](tel:+16472549788) View CAD Pricing [#pricing →](#pricing) - TSSA G1/G2 Licensed - 22 Years Experience - Same-Day GTA Dispatch - Written Workmanship Warranty ![Old cast iron sectional boiler being removed beside a newly installed condensing unit in a Toronto basement](/images/misc/old-cast-iron-sectional-boiler-being-broken-down-f.webp) - 5-Star Customer Satisfaction - Same-Day GTA Emergency Dispatch - 22 Years of Boiler Installation Experience - Written Workmanship Warranty ## What Is Boiler Replacement in Toronto? Boiler replacement in Toronto is the full swap of a 15 to 40 year old gas or oil boiler, and for older homes with original cast iron distribution it runs $8,500 to $14,500 CAD. Newer GTA hydronic and combi systems reaching end of life replace at $5,500 to $9,500 CAD. The word replacement understates what is involved. On a pre-1950 house the job includes breaking down and removing a cast iron sectional weighing several hundred kilograms, de-commissioning the masonry chimney for the boiler, running PVC direct venting, rebuilding the near-boiler piping, sizing the gas line in MBTU back to the meter, and adding the controls that let a condensing unit actually condense. Every replacement starts with a written repair-versus-replace analysis. That comparison is not a sales formality. Roughly one call in five ends with us quoting the repair instead, because a unit under fifteen years old with a sound heat exchanger and a single failed component is usually worth fixing. Every technician on the job holds a valid TSSA G1 or G2 gas certification and the work is completed to Ontario B149, CSA B51, and Ontario Building Code Part 6 and Part 7, the same code path we follow on every boiler installation in Toronto [/ →](/) . ![Corroded heat exchanger section pulled from a 30-year-old Toronto cast iron boiler showing rust and a visible crack](/images/misc/corroded-cast-iron-heat-exchanger-section-pulled-f.webp) ## 5 Signs Your Boiler Needs Replacement, Not Repair 1. **Rust staining or standing water at the base of the unit.** On a cast iron sectional this almost always means a cracked section. Sections can occasionally be replaced at $1,500 to $3,500 CAD, but on a 25 year old boiler you are spending major-repair money on a unit already past its efficient life. 2. **Pressure that needs topping up every few weeks.** A healthy closed hydronic system holds pressure for years. Frequent top-ups mean a leak, and if it is not visible on the loop it is inside the boiler. 3. **Condensation in a flue that should be dry.** A mid-efficiency boiler venting into masonry should keep its flue gases above the dew point all the way out. Moisture in that flue indicates a heat exchanger losing its ability to transfer heat. 4. **Gas bills climbing with no change in habits.** Efficiency degrades gradually. A unit that was 80 percent at installation can be running in the mid-sixties by year 25, and the bill is the only symptom you see. 5. **A second major repair inside two years.** Heat exchanger, gas valve, circuit board, cast iron sections. Any two of those on an older unit and the repair spend has started chasing the replacement cost. ## 7 Things Our TSSA Technicians Check Before Every Quote Before any replacement is quoted, the diagnostic covers seven specific items, and every one of them can change the CAD figure. 1. **Combustion readings.** CO, CO2 ratio, stack temperature, and excess air measured with a digital flue gas analyser to establish the unit’s real current efficiency, not its nameplate. 2. **Heat exchanger condition.** Visual inspection for cracking, scaling, and corrosion on the fire side and the water side. 3. **System pressure history.** How often it has needed topping up, and whether the expansion tank pre-charge is still correct. 4. **Distribution type and temperature.** Cast iron radiators, hydronic baseboard, panel radiators, or radiant slab. This sets whether a mixing valve and return-water protection are required. 5. **Venting route.** Whether PVC can be routed to a compliant side-wall or concentric termination given B149 clearances to windows, meters, and the property line. 6. **Gas line capacity.** Load in MBTU back to the meter, checked against the input rating of the proposed replacement. 7. **Removal route.** How the old unit physically leaves the building. On a Cabbagetown row house with no driveway this is agreed before install day, not improvised on it. ## How Much Does Boiler Replacement Cost in Toronto? | Scenario | What drives the price | CAD band | | --- | --- | --- | | Newer sealed condensing or combi at end of life | Existing PVC vent reused, minimal piping change | $5,500 - $9,500 | | Cast iron to condensing retrofit | Sectional removal, chimney de-commissioning, near-boiler rebuild | $8,500 - $11,500 | | Complex retrofit, high radiator count | Gravity conversion, zoning, full balance and air elimination | $11,500 - $14,500 | | Oil to gas conversion | Above plus oil tank and line decommissioning, new gas line | Quoted per site | Enbridge Home Efficiency Rebate Plus offsets up to $6,500 CAD and the Canada Greener Homes Grant up to $5,000 CAD on qualifying 95%+ AFUE replacements, for a combined offset of up to $11,500 CAD. The Canada Greener Homes Loan adds up to $40,000 CAD at zero percent interest. Both rebate programs require the energy assessment to happen before the old boiler is removed, which is the single most common way Toronto homeowners lose the offset. ## What Actually Stops Toronto Homeowners From Replacing an Aging Boiler “It still works” is the most common reason a replacement gets deferred, and it is a fair point mechanically. A cast iron sectional can run for fifty years. The problem is that it stopped being efficient around year 25, and every heating season after that costs 25 to 35 percent more than it needs to. Deferring a $10,000 CAD replacement for five years on a house burning $2,400 CAD of gas a year can easily cost $3,000 to $4,000 CAD in wasted fuel, and it risks losing the rebate offset if the unit fails mid-winter and gets replaced as an emergency instead of a planned upgrade. “The quote is huge” is the second. It is worth separating equipment from work. On a $10,300 CAD cast iron retrofit the boiler itself is often under half the total. The rest is removal, chimney de-commissioning, PVC venting, near-boiler piping, mixing valve, expansion tank, zone controls, permit, inspection, disposal, and rebate filing. Every one of those lines appears on the quote in Canadian dollars. “I cannot tell if the technician is licensed” is the third and the easiest to resolve. Ontario requires TSSA G1 or G2 for gas boiler work. Ask for the certificate number and check that it appears on the invoice, and ask for the TSSA permit number on the completed job. We print both as standard. ## How Our Toronto Boiler Replacement Process Works Diagnostic and assessment first, covering the seven checks above. Written repair-versus-replace analysis handed over before any quote is discussed. Removal plan and quote, so the route the old unit takes out of the building and the fate of the chimney are settled in advance. TSSA permit pulled with the inspection booked at the same time, and installation scheduled inside 3 to 7 business days or 24 to 48 hours where the house has no heat. Removal and installation, with the old sectional broken down and carried out, the new boiler set, near-boiler piping rebuilt, combustion analysed, and the system purged and rebalanced. Inspection, disposal, and warranty, with the TSSA inspector met, the old unit scrap recycled, the warranty registered, the rebates filed, and the written workmanship warranty issued. If the replacement is being driven by efficiency rather than failure, High-Efficiency Condensing Boiler Installation Toronto [/high-efficiency-boiler-installation-toronto/ →](/high-efficiency-boiler-installation-toronto/) covers the 95%+ AFUE side in full. If you want to free the utility room at the same time, Combi Boiler Installation Toronto [/combi-boiler-installation-toronto/ →](/combi-boiler-installation-toronto/) explains the tank conversion. Transparent CAD Pricing ## How Much Does Boiler Replacement Cost in Toronto? Published on the page, never gated. Every quote itemises parts, labour, TSSA permits, and disposal in Canadian dollars before any work starts. ### Newer System Replacement $5,500 - $9,500 CAD - Sealed condensing or combi unit at end of life - Existing PVC direct venting reused where sizing allows - Gas line check, isolation valves and sediment trap - Old unit disposal and scrap recycling included Get This Quoted [tel:+16472549788 →](tel:+16472549788) Most Requested ### Cast Iron to Condensing Retrofit $8,500 - $11,500 CAD - Cast iron sectional broken down and removed in sections - Chimney flue de-commissioned, PVC direct venting installed - Near-boiler piping rebuilt as a primary secondary loop - Mixing valve and return-water temperature protection Get This Quoted [tel:+16472549788 →](tel:+16472549788) ### Complex Retrofit, High Radiator Count $11,500 - $14,500 CAD - Everything in the cast iron retrofit - Gravity hot water conversion to pumped and zoned - Zone valves, circulators and full system balance - Pre-war radiator balancing and air elimination Get This Quoted [tel:+16472549788 →](tel:+16472549788) The $8,500 to $14,500 CAD band covers older Toronto cast iron retrofits. Newer GTA hydronic systems replace at $5,500 to $9,500 CAD. Every replacement includes a written repair-versus-replace analysis before you commit. ## Ontario Rebate Fast Filing Save Up to $11,500 CAD As an ENERGY STAR certified installer we process your utility and federal grant paperwork directly, so the offset lands on your quote instead of on your to-do list. Up to $6,500 CAD Enbridge Home Efficiency Rebate Plus Qualifying 95%+ AFUE installations paired with insulation upgrades. Up to $5,000 CAD Canada Greener Homes Grant Federal grant on qualifying high-efficiency heating equipment. Up to $40,000 CAD Canada Greener Homes Loan Interest-free financing at 0% over 10 years. Why Choose Us ## Why Choose Us for Boiler Replacement ### 22 Years of Boiler Installation Experience Two decades of end-of-life replacements, cast iron conversions, and gravity system retrofits across Toronto and the GTA. ### Written Repair-Versus-Replace, Every Time If the repair is the better value we quote the repair. The comparison is written down so you are not deciding on a verbal opinion. ### Removal Planned Before Install Day On row houses and narrow lots the old sectional is broken down and carried out in pieces. The method is agreed at the assessment. ### TSSA G1/G2 Licensed Technicians Only Ontario B149 fuel code, CSA B51, and Ontario Building Code Part 6 and Part 7 on every replacement. ### Disposal and Scrap Recycling Included Removal, haul-away, and scrap recycling of the old unit are in the quoted price, not billed as an extra afterwards. ### Published CAD Pricing $8,500 to $14,500 CAD for older Toronto cast iron retrofits, $5,500 to $9,500 CAD for newer systems. Published, not gated. The Framework ## How Our Boiler Replacement Process Works 1. 1 ### Diagnostic and assessment Combustion analysis, visual heat exchanger inspection, pressure history, and current AFUE recorded against the home's age and distribution type. 2. 2 ### Written repair-versus-replace Repair cost set against remaining service life, projected gas savings from a 95%+ AFUE unit, and the rebate offset. In writing, in CAD. 3. 3 ### Removal plan and quote How the old unit leaves the basement, what happens to the chimney, and whether the gas line needs resizing. All priced before install day. 4. 4 ### TSSA permit and scheduling Permit pulled, inspection booked at the same time, install within 3 to 7 business days or 24 to 48 hours on a no-heat emergency. 5. 5 ### Removal and installation Old sectional broken down and carried out, new boiler set, near-boiler piping rebuilt, combustion analysed, system purged and rebalanced. 6. 6 ### Inspection, disposal and warranty TSSA inspection met, old unit scrap recycled, warranty registered, rebates filed, written workmanship warranty issued. ## Want a written CAD quote for boiler replacement? Published pricing bands, TSSA-licensed technicians, and the diagnostic waived on same-visit authorisation. (647) 254-9788 [tel:+16472549788 →](tel:+16472549788) Get CAD Quote [/contact/ →](/contact/) Our Work ## Boiler Replacement Work Across Toronto and the GTA Click any image to enlarge. Customer Feedback ## What Customers Say About Our Boiler Replacement Work > Twenty-eight year old sectional, finally cracked. They gave us the repair-versus-replace in writing, we chose replacement, and the new condensing unit went in for $10,300 CAD with the old one hauled away. Leonard P. Guildwood 5-Star Customer Satisfaction > The part I appreciated was the removal plan. Row house, no driveway, and they explained exactly how the old boiler was coming out before we signed anything. $9,700 CAD. Rosa V. Cabbagetown Top-Rated Contractor > Gravity system from the 1940s converted to pumped and zoned. Every radiator heats evenly now. $13,400 CAD and they handled both rebate applications. Tariq H. The Kingsway Trusted by Homeowners and Businesses Got Questions? ## Boiler Replacement FAQs ### How much does boiler replacement cost in Toronto? An older Toronto cast iron retrofit runs $8,500 to $14,500 CAD. A newer GTA hydronic or combi system at end of life replaces at $5,500 to $9,500 CAD. The difference is not the boiler itself, it is everything around it: breaking down and removing a cast iron sectional, de-commissioning the masonry chimney, rebuilding the near-boiler piping as a primary secondary loop, and adding a mixing valve with return-water temperature protection so the new condensing unit can actually condense. Combined Enbridge and federal rebates offset up to $11,500 CAD on qualifying work. ### How old should a boiler be before I replace it? A cast iron sectional lasts 30 to 50 years mechanically but drops to 60 to 70 percent efficiency by year 25. A wall-mounted condensing unit lasts 15 to 20 years. The replacement decision is rarely about whether it still runs. At 25 years and beyond, the efficiency gap against a modern 95%+ AFUE unit is 25 to 35 percent of your gas bill, and the combined Enbridge and federal rebates of up to $11,500 CAD normally bring the payback inside 6 to 10 years. Below 15 years on a condensing unit, repair is usually the better value and we will say so. ### What is a written repair-versus-replace analysis? It is a one-page comparison we hand over at the end of every diagnostic. On one side is the cost of the repair in CAD and the realistic remaining service life of the unit given its age, its current combustion readings, and the condition of the heat exchanger. On the other is the installed cost of replacement, the projected annual gas saving from a 95%+ AFUE unit, and the rebate offset. It exists so the decision is made on numbers rather than on whoever is standing in your basement sounding confident. ### 5 signs your boiler needs replacement, not repair One, visible rust staining or water at the base of the unit, which usually means a cracked section. Two, system pressure that needs topping up every few weeks, indicating a leak inside the boiler or the loop. Three, condensation inside a flue that should be dry, a sign of a failing heat exchanger. Four, gas bills climbing year over year with no change in thermostat habits or occupancy. Five, a second major repair inside two years on a unit already past 25 years. Any one of these justifies the conversation. Three or more and replacement is almost always the right call. ### Can I keep my cast iron radiators? Yes, and in most pre-1950 Toronto homes you should. Cast iron column radiators deliver quiet, even heat and replacing them with ductwork means opening plaster walls across the whole house. They pair with a condensing boiler once you add an outdoor reset curve, a mixing valve, and return-water temperature protection to keep the return water cool enough for the boiler to condense. That conversion is the $8,500 to $14,500 CAD band. See Hydronic Heating and Radiator Installation Toronto for the distribution detail. ### What happens to my chimney? A condensing boiler vents through PVC, not masonry, because its exhaust is cool and acidic and would destroy an unlined flue. The chimney connection is cut and capped and the flue is de-commissioned for the boiler. If a gas water heater still vents into that chimney, the liner has to be resized for a single appliance, because a flue sized for two appliances will not draft correctly with one. That resize is quoted in scope at the assessment. ### Do you handle removal and disposal of the old boiler? Yes, and it is in the quoted price. On a cast iron sectional the unit is broken down in the basement and carried out in sections rather than winched whole up a stairwell, which matters in Riverdale and Cabbagetown row houses with no driveway. The sections go for scrap recycling. Haul-away, disposal, and site clean-up are never billed as an extra afterwards. ### Will the gas line need resizing? Sometimes. Gas lines are sized in MBTU for the appliance load they serve, and a replacement with a different input rating can exceed what the existing run supports, particularly on a combi conversion. We calculate the load back to the meter at the site assessment. If a resize is needed it appears on the quote before anything is ordered, along with the isolation valve and sediment trap. ### Cast iron versus condensing: 5 considerations for older Toronto homes One, efficiency, where a 25 year old cast iron unit runs 60 to 70 percent against 95 percent plus for condensing. Two, distribution temperature, because cast iron radiators were designed for 180F supply and need a mixing valve to let a condensing boiler work properly. Three, venting, since condensing means PVC and de-commissioning the chimney. Four, mechanical room footprint, where a wall-mounted condensing unit frees the floor space a sectional occupied. Five, rebates, which apply only above the 95 percent AFUE threshold. A like-for-like cast iron replacement is still possible but carries no rebate value and locks in the fuel cost for another 30 years. ### How long does a replacement take? A newer system replacement is one working day. A cast iron retrofit with chimney de-commissioning and rebuilt near-boiler piping usually runs one and a half to two days. Scheduling is 3 to 7 business days after quote approval, or 24 to 48 hours when the house has no heat. The TSSA inspection is booked at the same time as the permit so nothing sits half-commissioned. ### Do you replace oil boilers as well as gas? Yes. Oil to gas conversions are common in older Toronto and Etobicoke homes and involve decommissioning the oil tank and line, running and sizing a new gas line back to the meter, and venting the new condensing unit through PVC. The heating side of the job is the same as any cast iron retrofit. The additional oil decommissioning work is itemised separately on the quote. ### What warranty comes with a replacement? A written workmanship warranty on our labour and the manufacturer warranty on parts. The unit is registered with the manufacturer at commissioning and all parts come from Ontario distributors, which is what keeps that parts coverage valid. Annual servicing is a condition of most manufacturer warranties, so the 12-point tune-up at $199 to $349 CAD is worth keeping on the calendar. ### Still have a question about your boiler? Talk to a TSSA-licensed technician. Same-day GTA dispatch, 4-hour cold-snap response. (647) 254-9788 [tel:+16472549788 →](tel:+16472549788) Request Written Installation Quote [/contact/ →](/contact/) ## Related Services ![Wall-mounted 95%+ AFUE condensing boiler installed in a Toronto basement with copper near-boiler piping and PVC flue](/images/misc/wall-mounted-95-percent-afue-condensing-boiler-new.webp) ### High-Efficiency Condensing Boiler Installation Toronto 95%+ AFUE condensing boiler installation with 316L stainless heat exchangers, PVC side-wall venting, and full Enbridge plus Canada Greener Homes rebate coordination across Toronto and the GTA. View service [High-Efficiency Condensing Boiler Installation Toronto →](/high-efficiency-boiler-installation-toronto/) ![Wall-mounted combi boiler installed in a compact Toronto utility room with isolation valves and domestic hot water piping](/images/misc/compact-wall-mounted-combi-boiler-installed-in-a-s.webp) ### Combi Boiler Installation Toronto Compact wall-mounted combi boilers delivering uninterrupted heating and on-demand domestic hot water, sized by GPM for Toronto homes and fitted with descaling valves for GTA hard water. View service [Combi Boiler Installation Toronto →](/combi-boiler-installation-toronto/) ![Restored cast iron column radiator with a thermostatic radiator valve in a pre-war Toronto living room](/images/misc/restored-cast-iron-column-radiator-with-a-thermost.webp) ### Hydronic Heating and Radiator Installation Toronto Hydronic distribution design and radiator installation: cast iron column radiators, baseboard convectors, thermostatic radiator valves, and oxygen-barrier PEX manifolds, balanced and air-eliminated. View service [Hydronic Heating and Radiator Installation Toronto →](/hydronic-heating-installation-toronto/) ![](/images/misc/tssa-licensed-technician-closing-the-front-panel-o.webp) Same-Day Emergency Dispatch, 24/7 Cold Snap Response ## Ready to Book Boiler Replacement in Toronto? Every boiler replacement quote itemises parts, labour, TSSA permits, and disposal in Canadian dollars before any work starts. Call (647) 254-9788 [tel:+16472549788 →](tel:+16472549788) Request Written Installation Quote [/contact/ →](/contact/) - Written workmanship warranty - Published CAD pricing, no quote gating - TSSA G1/G2 licensed technicians