Quick answer
Replacing a furnace and air conditioner together in the GTA typically runs $7,500–$11,500 installed, depending on efficiency tier and home size. Bundling saves roughly $1,000–$2,500 against two separate installs because one crew mobilization, one set of sheet-metal transitions, one gas and electrical hookup and one permit cycle cover both units instead of two.
A furnace and AC combo costs $7,500–$11,500 installed for most homes in Burlington, Oakville and Hamilton. That covers a high-efficiency furnace, a matched condenser and indoor evaporator coil, the sheet-metal transition between them, gas and electrical connections, the permit and commissioning. Where you land in the band comes down to home size, the efficiency tier you choose, and how much of the existing plenum and line set survives.
What the $7,500–$11,500 combo price buys
- Furnace on its own: $4,500–$7,500 installed for a high-efficiency unit, with most GTA replacements clustering at $4,500–$6,500
- Central air on its own: $3,500–$7,500 installed when the ducts are already there and in good condition
- The two together: $7,500–$11,500, because the overlapping labour is only paid for once
- Larger homes with top-tier modulating equipment: combined installs can reach the $9,500–$15,000 range
Why doing both at once saves $1,000–$2,500
The saving is mechanical, not a discount. Your evaporator coil sits inside the supply plenum directly on top of the furnace. Swap the furnace alone and that coil still has to come out, the line set gets re-brazed and the plenum re-sealed — then the identical work happens again a year later when the condenser quits.
The rest is scheduling: one crew mobilization, one set of custom sheet-metal transitions, one gas and electrical hookup session, and one permit cycle rather than two. That also means one municipal inspection booked instead of two, and one day the house is opened up instead of two.
Why Millcroft and Glen Abbey get combo quotes and Aldershot often does not
In the 1970s–90s subdivisions — Millcroft, Glen Abbey, River Oaks — the furnace and the air conditioner usually went in together, and the first time they were replaced they were often replaced together too. Two units of the same age tend to reach end of life within a season or two of each other, which is why a February no-heat call on those streets so often turns into a combo quote.
Aldershot and Roseland are different. In those 1950s–60s bungalows the central air was usually added years after the original furnace, sometimes by a different contractor, so the two units are on different clocks and bundling them is not automatic.
What pushes a combo quote up
- Efficiency tier — a two-stage or modulating furnace paired with a higher-SEER2 condenser sits at the top of the band. Read what SEER2 rating you need in Ontario before you pay for it.
- Refrigerant — new condensers ship with A2L refrigerants (R-32 or R-454B) and need a matched indoor coil, and the existing line set has to be checked for size and condition before it is reused. Here is what the A2L change means.
- Venting — a mid-efficiency furnace that vented into a masonry chimney becomes a high-efficiency furnace vented in PVC through the side wall, and if a water heater still uses that chimney it needs a liner.
- Ductwork — an undersized return or a trunk built for a 1980s furnace may need reworking before a modern variable-speed blower performs as rated.
- Permits — municipal fees vary and typically run $100–$300.
- Electrical — a larger condenser can need a new breaker and outdoor disconnect.
The bottom of the range is a like-for-like swap: a single-stage 96% AFUE furnace going into an existing PVC side-wall vent, a base-tier condenser at the 13.4 SEER2 minimum, a plenum that only needs a new coil cabinet, and a line set that passes a pressure test and can be flushed and reused. Every item on the list above moves the quote toward the top.
When splitting them up is the better call
If one unit is young, do not scrap it for the sake of the bundle. A seven-year-old condenser with a healthy compressor has years in it, and the bundling saving does not cover throwing it away. The combo makes sense when both units are past 12 years, or when a failure on one has already put you in front of a quote.
It is also worth pricing a heat pump before committing. A cold-climate heat pump paired with a furnace handles the cooling and most of the heating, and it is the part of the job the rebate money is aimed at: current Ontario programs return $500–$7,500 depending on the system, and the current program is aimed at heat pumps rather than gas furnaces and conventional condensers — check the program page before counting on anything for a straight furnace-and-AC swap. Our heat pump vs. furnace comparison lays out the math for this climate, and the current rebate programs page has the live terms.
Common questions about combo pricing
- Does one permit cover both? Where the municipality requires one, normally yes — a furnace and condenser installed on the same day go on one HVAC permit with one inspection. Replace the condenser on its own a year later and it needs its own permit and its own inspection visit, which is part of what the bundle saves.
- Can it be financed? Yes. Lending partners write HVAC terms from 12 months to 15 years, and a $12,000 furnace-and-AC package over 10 years lands near $140–$170 a month depending on the rate. Our partners carry no prepayment penalty, so a rebate cheque can go straight onto the principal.
- How long does it take? One full day for a straight swap, two when the venting changes from a chimney to PVC or the plenum is rebuilt. The furnace goes in first so the coil cabinet can be set on top of it, and the condenser and line set are finished after the indoor side is sealed.
- Who files the rebate paperwork? We do, as part of the job — and we tell you up front when the equipment you are choosing does not qualify, so the rebate line on the quote is a real number rather than a footnote.
- Is a matched system worth insisting on? Yes — the SEER2 rating is certified for a specific coil-and-condenser pairing, and an unmatched pairing loses the rating and can put the manufacturer's warranty at risk.
ZK Mechanical is owner-operated out of 4145 North Service Road in Burlington, and every combo price is written down before anything is ordered. See our heating services and air conditioning pages, call (647) 801-1252, or request a quote.