Ontario's Plain-English Guide to Custom Home Building📞 705-533-1633 | ☎️ 1-866-868-6606 | ✉️ info@icfhome.ca
Free tool Heating and cooling 2026 prices
Furnace and AC Replacement Cost Calculator for Ontario
Pick the furnace, the cooling and the extras. The calculator adds them up using our 2026 Ontario price ranges.
Short version: A new high-efficiency gas furnace usually costs about $4,000 to $9,000 installed in Ontario in 2026. Central AC adds $3,500 to $8,500, a heat pump instead of AC $7,000 to $18,000. Doing furnace and AC together is often $6,500 to $12,500.
Price your system
Sizing: a straight swap usually keeps the old capacity, but older systems are often oversized. A heat loss calculation tells you the real size; try the Ontario heat loss calculator.
Where the numbers come from
Ranges come from our 2026 Ontario guides: Furnace replacement cost in Ontario and Central air conditioning cost in Ontario. They assume existing ductwork; new ducts cost more.
Before you sign a quote
- Ask whether the installer did a heat loss calculation or just matched the old size.
- Check the warranty: parts and labour, and for how long.
- Check rebates first: Home Renovation Savings Program 2026.
- Comparing a heat pump with gas? Try the heat pump vs gas cost calculator.
Questions people ask
How much does a new furnace cost in Ontario in 2026?
A high-efficiency gas furnace usually costs about $4,000 to $9,000 installed; a straightforward swap in a 2,000 sq ft house is often $5,000 to $7,500.
How much is a furnace and AC together?
Replacing both in one visit with existing ducts usually runs about $6,500 to $12,500 in Ontario.
What size furnace or AC do I need?
The right size comes from a heat loss and heat gain calculation, not the size of the old unit. Many older homes have oversized equipment.
Do I need a permit to replace a furnace?
A like-for-like swap often needs none, but some municipalities require one; where needed it is usually about $90 to $350.
Related guides on BuildersOntario
Building in Simcoe County or on Georgian Bay?
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Updated November 2026. Planning ranges, not quotes. Get at least three written quotes from licensed HVAC contractors.
