Definition — how each system delivers heat
A forced-air furnace burns natural gas (or propane in rural areas), heats air inside a heat exchanger, and blows that air through ducts to registers throughout the home. Dominates GTA new-build since the 1970s.
A boiler heats water and circulates it through radiators, radiant floor loops, or baseboards. Common in older Toronto and Scarborough century homes and in most condos with in-slab heating.
A cold-climate heat pump moves heat from outdoor air (even at –15 °C) into the home using a refrigerant loop. Delivers heat through either ductwork (a central heat pump) or wall-mounted indoor heads (a ductless mini-split).
When to choose which
Forced-air furnace: your home already has ductwork, natural gas is at the meter, and you want the lowest total install cost. Adds cooling easily with a matching AC or coil.
Boiler: your home has existing hydronic radiators or in-floor tubing, you want silent radiant comfort, and you don't mind adding a separate mini-split or central AC for summer.
Heat pump: you want to reduce or eliminate on-site combustion, your electrical service can support the load, and you value the single-system efficiency of one machine handling both heating and cooling.
Hybrid (heat pump + gas furnace, aka 'dual fuel'): often the pragmatic GTA pick when a working furnace already exists — you cool with the heat pump in summer, heat with the heat pump above the balance point, and let the furnace take over on the coldest weeks.
Failure modes — the systems each one struggles with
Furnaces struggle with humidity in shoulder seasons and can feel 'blast then silence' on single-stage models. Under-sized ducts amplify the problem.
Boilers struggle with cooling (they simply can't) and with modern zoning if the original piping wasn't laid out for zones. Radiators can be slow to react to setback strategies.
Heat pumps struggle when they're under-sized for the home's design temperature — the electric-strip backup runs constantly and drives the electric bill through the roof. That is almost always a sizing/installer error, not a technology limitation.
Proof — running costs in an average GTA home
Natural gas remains, on average, the cheapest per-BTU heating fuel in Ontario for a properly sized modern furnace. A cold-climate heat pump above its balance point beats a gas furnace on fuel cost per BTU during shoulder seasons but not during the deep-winter cold snaps.
Total-cost comparisons must include install cost, expected life, backup fuel cost, and any available rebates. Without those inputs, no honest comparison is possible. [GATHER: current provincial + federal rebate landscape as of July 2026]
Action — how Metroheat quotes multi-system comparisons
For homeowners doing full-system replacements we quote three scenarios on the same page: high-efficiency furnace + central AC, hybrid heat pump + existing/new furnace, and cold-climate heat pump only. Each includes install cost, expected annual utility cost using your actual rates, and any rebate we can confirm at time of quote.
That is the only way to make an informed decision. Ready to see the numbers? Contact Metroheat at (416) 283-5698.