ZK Mechanical Answer Hub
Your HVAC questions, answered honestly
One question per page. Real prices, real trade-offs, and GTA-specific advice from licensed technicians — no fluff, no sales script. If you'd ask it of a technician standing in your basement, you'll find it here.
38 answers
HeatingHow much does furnace repair cost in Toronto?
Most furnace repairs in Toronto and the GTA cost between $150 and $800.
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HeatingHow long does it take to install a new furnace?
A straightforward like-for-like furnace replacement takes 4 to 8 hours — one working day.
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HeatingWhy is my furnace leaking water?
The most common cause is a clogged or disconnected condensate drain on a high-efficiency furnace, which produces water as a normal by-product.
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HeatingWhy is my furnace making a loud banging or squealing noise?
A single boom at startup usually means delayed gas ignition; metallic banging from ducts is normal expansion.
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HeatingWhat's included in a furnace tune-up in Ontario?
A proper furnace tune-up includes cleaning the burners and flame sensor, inspecting the heat exchanger for cracks, testing gas pressure and temperature rise, checking the igniter, blower motor and capacitor, flushing the condensate drain, replacing or checking the filter, testing safety controls and carbon monoxide levels, and calibrating the thermostat.
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HeatingHow long does a furnace last in Ontario?
A gas furnace in Ontario typically lasts 15 to 20 years.
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HeatingWhy is my furnace not turning on?
The most common reasons a furnace won't turn on are a thermostat issue, a tripped breaker, a flipped furnace power switch, a clogged filter, or a full condensate trap triggering the safety shut-off.
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CoolingHow long does an air conditioner last in Canada?
A central air conditioner in Canada typically lasts 12 to 15 years, with well-maintained units reaching 18–20.
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CoolingIs a ductless mini-split worth it in Toronto?
Yes — for homes without ductwork, condos, additions, finished attics, and basement apartments, a ductless mini-split is usually the most practical and efficient option in Toronto.
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CoolingWhy is my house so humid even with the AC on?
An air conditioner that cools but doesn't dehumidify is usually oversized — it satisfies the thermostat too quickly to wring moisture from the air.
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CoolingShould I replace my furnace and AC at the same time?
If both units are over 12 years old, replacing them together usually saves $1,000–$2,500 versus two separate installs, since labour, sheet-metal work, and permits overlap.
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CoolingHow long does air conditioner installation take?
A straightforward central AC replacement takes 4 to 8 hours — most of a single day for a GTA crew swapping an existing system on matched ductwork.
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CoolingHow much does AC repair cost in the GTA?
Most AC repairs in the GTA run $150 to $800, depending on the part.
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Water HeatersShould I rent or buy a water heater in Ontario?
Buying almost always costs less over the unit's life.
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Water HeatersHow long does a water heater last in Ontario?
A conventional tank water heater in Ontario lasts 8 to 12 years on average; tankless units last 15 to 20 years.
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Water HeatersWhy is my water heater not producing hot water?
On a gas water heater, the most common causes are a blown-out pilot light, a failed thermocouple, or a faulty gas control valve.
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Water HeatersWhat size tankless water heater do I need?
Size a tankless water heater by flow rate: in the GTA's cold groundwater, expect a 75°F (42°C) winter temperature rise.
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Water HeatersHow much does it cost to replace a water heater in Ontario?
Replacing a tank water heater in Ontario costs $1,200–$2,500 installed; a tankless unit runs $3,500–$6,500.
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Water HeatersIs a tankless water heater worth it in Ontario?
A tankless water heater is worth it in Ontario if you value endless hot water, want to reclaim floor space, and plan to stay in your home long enough to recoup the higher upfront cost.
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Air Quality & DuctsHow much does duct cleaning cost in the GTA?
Professional duct cleaning for a typical GTA house costs $300 to $700, depending on home size, number of vents, and system accessibility.
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Air Quality & DuctsHow often should air ducts be cleaned?
Every 3 to 5 years is a reasonable interval for most GTA homes — duct cleaning is not an annual service, despite what telemarketers suggest.
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Air Quality & DuctsDo I need a humidifier in winter in Toronto?
Most Toronto homes with forced-air heating drop to 15–25% relative humidity in January — well below the healthy 30–40% winter range.
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EmergencyWhat should I do if my heat stops working at night in Toronto?
First check the simple causes: thermostat batteries and settings, the furnace power switch, the breaker, and the filter.
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EmergencyDoes emergency HVAC service cost more than regular service?
Usually, yes.
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EmergencyCan my furnace leak carbon monoxide?
Yes.
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EmergencyCan I get same-day furnace repair in the GTA?
Yes.
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EmergencyWhat counts as an HVAC emergency?
An HVAC emergency is anything that threatens safety, health, or your home: no heat in winter, any gas smell, suspected carbon monoxide, a major water leak from your system, or no cooling during a heat warning when vulnerable people are home.
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EmergencyWhat should I do if I smell gas in my house?
Leave the building immediately.
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Costs & BuyingHow do I choose a good HVAC contractor in the GTA?
Verify TSSA gas licensing and liability insurance, confirm they pull permits, and get itemized written quotes from two or three companies.
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Costs & BuyingCan I finance a new furnace or air conditioner in Ontario?
Yes.
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Costs & BuyingAre HVAC maintenance plans worth it?
For most homeowners with equipment over 5 years old, yes.
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Costs & BuyingWhy are my heating bills so high this winter?
Beyond rate increases, the usual culprits are an aging or poorly maintained furnace losing efficiency, a clogged filter forcing longer run times, leaky ductwork dumping heated air into the basement, air leaks around doors and attic hatches, and thermostat habits like heating an empty house.
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Costs & BuyingWhy is one room in my house always cold?
A chronically cold room usually means weak airflow to that room: a closed or blocked damper, crushed or leaky duct run, or a register hidden under furniture.
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Costs & BuyingHow much does a heat pump cost in Ontario?
A cold-climate heat pump in Ontario typically costs $6,000–$16,000 installed before rebates, depending on system size, whether it's ducted or ductless, and whether it replaces or works alongside your furnace.
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Costs & BuyingHow much does an HVAC service call cost in the GTA?
An HVAC service call in the GTA typically costs $90–$150 for the diagnostic fee, which covers a technician coming out and finding the problem.
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Costs & BuyingAre HVAC estimates and quotes free in the GTA?
Yes — quotes for a new furnace, air conditioner, or heat pump installation are almost always free in the GTA, including in-home assessments and itemized written pricing.
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Costs & BuyingDoes the furnace brand really matter?
Less than you'd think.
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Costs & BuyingShould my HVAC technician be licensed and insured in Ontario?
Yes, absolutely.
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