The 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.
Heating
How much does furnace repair cost in Toronto?
Most furnace repairs in Toronto and the GTA cost between $150 and $800.
Read the full answerHow long does it take to install a new furnace?
A straightforward like-for-like furnace replacement takes 4 to 8 hours — one working day.
Read the full answerWhy 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.
Read the full answerWhy 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.
Read the full answerWhat'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.
Read the full answerCooling
How 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.
Read the full answerIs 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.
Read the full answerWhy 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.
Read the full answerShould 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.
Read the full answerWater Heaters
Should I rent or buy a water heater in Ontario?
Buying almost always costs less over the unit's life.
Read the full answerHow 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.
Read the full answerWhy 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.
Read the full answerWhat 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.
Read the full answerAir Quality & Ducts
How 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.
Read the full answerHow 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.
Read the full answerDo 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.
Read the full answerEmergency
What 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.
Read the full answerDoes emergency HVAC service cost more than regular service?
Usually, yes.
Read the full answerCan my furnace leak carbon monoxide?
Yes.
Read the full answerCosts & Buying
How 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.
Read the full answerCan I finance a new furnace or air conditioner in Ontario?
Yes.
Read the full answerAre HVAC maintenance plans worth it?
For most homeowners with equipment over 5 years old, yes.
Read the full answerWhy 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.
Read the full answerWhy 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.
Read the full answerDidn't Find Your Question?
Check our quick FAQ for short answers, browse in-depth guides on the blog, or just ask us — a licensed technician answers every inquiry.