Heating and cooling

Heating and Air Conditioning Services for Ontario Homes

Kelvin Mechanical installs, repairs and maintains furnaces, air conditioners, heat pumps, ductless systems and boilers across the GTA and nearby Ontario. This page helps you work out where to start, then sends you to the right service.

Book a heating or cooling visit +1 905-407-7353

Close-up of an outdoor air conditioner condenser with its rating plate and Kelvin Mechanical service labels

Furnace and heat

Furnace InstallationA furnace that suits your home starts with a load calculation, not a guess. We review sizing, venting, gas supply...View page Furnace RepairFurnace not heating, clicking or shutting off after a few seconds? We trace the symptom to the failed part, explain...View page Furnace MaintenanceA furnace check should be more than a filter swap. We inspect burners, ignition, venting and safety controls...View page Boilers / Hydronic HeatingHot-water heating calls for different thinking than forced air. We repair, install, replace and service boilers...View page Garage / Workshop HeatersHeating a garage is a different problem from heating a house. We help you choose between a gas unit heater, electric...View page

Cooling and heat pumps

AC InstallationCentral air and split-system installs planned around your house, your ductwork and your electrical service...View page AC RepairWarm air, a frozen coil or an outdoor unit that will not start: we trace the fault first, then explain whether a repair...View page AC MaintenanceA spring tune-up should look at more than the filter. We work through coils, electrical parts, drain, airflow...View page Heat Pump InstallationA heat pump can heat and cool a home, but only if it is sized, matched and commissioned properly. We plan around...View page Heat Pump RepairFrost on the outdoor unit, weak heat or an error on the thermostat: we find the cause before replacing parts. Emergency...View page Heat Pump MaintenanceA heat pump works in January and in July, so it needs more attention than an air conditioner alone. We check coils...View page

Ductless, controls and more

Ductless InstallationNo ducts needed. A ductless mini split heats and cools a room, a floor or a whole home, using a wall-mounted head...View page Ductless RepairBlinking lights, water on the wall or a head that ignores the remote: we trace the fault and tell you honestly whether...View page Ductless MaintenanceMini splits collect dust and moisture where you cannot see it. A simple owner routine plus a technician deep clean...View page Smart ThermostatsA smart thermostat only works as well as its wiring and compatibility. We match the thermostat to your furnace, air...View page Gas LinesAdding a furnace, tankless water heater, range, BBQ or generator adds gas load. We plan the line, size it for total...View page Emergency Heating / CoolingNo heat in winter or no cooling in a heat wave is stressful. Start with a few safe checks...View page

In pictures

What this work looks like

Outdoor air conditioner with service labelKelvin service sticker fitted

Furnace with a coil cabinet and new ductworkClean sheet-metal transitions

Kelvin job photo

Ductless indoor headWall-mounted, with the line set in a neat cover

Photos from Kelvin Mechanical jobs in the GTA and nearby Ontario.

Repair, maintenance or replacement: a plain way to decide

Most heating and cooling calls fall into one of three groups. The right one depends on the equipment's condition, its repair history and what you want from the system next.

Repair fits when the fault is specific, parts are available and the rest of the system is in sound condition. Start with furnace repair, AC repair or heat pump repair.
Maintenance fits when the system works but has not been checked lately. A yearly tune-up catches worn parts and airflow problems before a cold snap or heat wave. See furnace maintenance.
Replacement fits when repairs keep recurring, safety is in question, comfort is uneven or the equipment no longer suits the home. A proper load calculation, not a square-foot rule, sizes the new system.
A heat pump is worth considering at replacement time, on its own, as a ductless system or paired with a furnace. Eligible Ontario customers may qualify for rebates depending on the program rules, equipment, property and funding available at the time. See rebate eligibility.

What a first heating or cooling visit looks like

A first visit is a conversation and an inspection. We ask what is happening, look at the equipment and the home around it, and explain what we find in plain language.

A diagnostic fee may apply; confirmed at booking. A quote for new equipment follows a site review, because pricing varies with equipment, venting, ductwork, installation complexity and warranty options.

Equipment details: model, age, fuel type and service history
Airflow: filters, ducts, registers, returns and static pressure where needed
Venting, combustion air and gas connections for fuel-fired equipment
Thermostat settings and controls
Electrical supply for heat pumps and air conditioners
Your comfort questions: cold rooms, noise, humidity and running costs

How the heating and cooling pages connect

Each service has its own page with scope, steps and common questions. These are the ones homeowners ask about most.

Furnaces: installation, repair and maintenance
Air conditioning: central AC installation, repair and seasonal tune-ups
Heat pumps: installation, repair and maintenance for heating and cooling in one system
Ductless mini splits: installation, repair and maintenance, including homes without ducts
Boilers and hydronic heating for radiators and in-floor systems
Garage and workshop heaters for attached and detached spaces
Gas lines for appliances, heaters and equipment connections
Smart thermostats: setup and compatibility with your system
Emergency heating and cooling: no heat or no cooling, subject to availability

Ontario notes

Heating and cooling in Ontario: what to know before you decide

Cold winters and hot humid summers

Ontario equipment works hard at both ends of the year. Furnaces and heat pumps run for months through cold snaps, then air conditioners face heat and humidity. Sizing should reflect real heat loss and heat gain, not floor area alone. An oversized system tends to cycle often, which can hurt comfort and humidity control.

Older homes and their ductwork

Many Ontario homes were built between the 1950s and 1990s, and their ducts were often designed for smaller airflows. Weak return air, long runs and leaks are common. A new furnace, air conditioner or heat pump performs better when the duct system is reviewed first. We measure airflow rather than assume the old layout is fine.

Gas, propane and electricity

Natural gas is the main heating fuel across much of the GTA, with Enbridge Gas as the main utility. Homes beyond the gas network often use propane or electricity. Heat pump running costs compared with gas depend on both rates and your electricity plan, and these change. Ask for the comparison based on your own bills.

Codes, permits and regulated work

Gas, electrical and refrigerant work are regulated in Ontario, and permit rules vary by municipality. Kelvin Mechanical works with licensed and qualified professionals and trade partners, depending on the project scope. Ask any contractor who pulls the permit, who does the gas and electrical work, and what happens at inspection.

Help centre

Common questions

I am not sure what I need. Where do I start?

Start with the symptom or the goal. If something is broken, open the repair page for that system. If you are planning an upgrade, use Build My Quote and a site review will confirm the details.

Can a heat pump replace my furnace and air conditioner?

In many homes it can, but not all. Sizing needs a load calculation, performance depends on the model and the conditions, and some homes do better with a hybrid setup that keeps a furnace for backup. A site review confirms what suits your home.

Do you offer emergency heating and cooling?

Yes, emergency service is subject to availability. Call +1 905-407-7353 and describe the problem. If you smell gas, leave the building and call your gas utility or 911 from outside first.

How often should I service my furnace and air conditioner in Ontario?

Once a year for each is the usual schedule: the furnace before the heating season and the air conditioner before the cooling season. A heat pump does both jobs, so it benefits from a yearly check that covers both modes. Follow the manufacturer's instructions, because some warranties ask for service records. See furnace maintenance and AC maintenance.

How long does a furnace or air conditioner last in Ontario?

Gas furnaces are often expected to last roughly 15 to 20 years and central air conditioners somewhere around 12 to 15, but the range is wide. Installation quality, maintenance, run time and dust all matter. Age alone does not decide replacement. Condition, repair history and safety carry more weight, and a site review gives you a straight read.

Should I replace my furnace and air conditioner at the same time?

Often it makes sense, because the indoor coil, blower and thermostat have to work together. A new air conditioner paired with an old furnace blower can limit performance. It depends on the age of each unit and your plans. If only one is failing, we can explain what a matched upgrade later would involve. Start with Build My Quote.

Do I need a permit to replace a furnace or air conditioner in Ontario?

It depends on the municipality and the scope of work. Gas work is regulated in Ontario, and some cities require HVAC or building permits for replacements while others handle them differently. Rules differ by municipality and change, so we confirm what applies in places such as Toronto, Mississauga or Hamilton before work starts. Permits and inspections are arranged where required.

What is the difference between a heat pump, a furnace and a hybrid system?

A furnace burns natural gas or propane to make heat. A heat pump moves heat using electricity and also cools in summer. A hybrid pairs a heat pump with a furnace that takes over when it gets very cold. Which one suits you depends on your ductwork, electrical service, energy rates and comfort goals. Our heat pump selection guide compares them.

I rent my home. Who should arrange heating or cooling repairs?

In most rentals, tell your landlord or property manager first, because they usually control the equipment and the repair process. Ontario landlords have responsibilities around providing heat, and many municipalities have heat bylaws. If your furnace or water heater is rented from a third party, that company may need to do the work. Property managers can see property management HVAC.

How do I get my heating and cooling ready for an Ontario winter?

Replace or clean the furnace filter, keep registers and returns clear, test your carbon monoxide and smoke alarms, and clear snow and ice from outdoor vent pipes and heat pump units. Book a furnace check before the first deep cold, when call volumes rise. Note any noises or smells and mention them at the visit. See furnace maintenance.

Do you provide heating and cooling service outside Toronto?

Kelvin Mechanical serves the GTA and nearby Ontario, including Mississauga, Brampton, Vaughan, Markham, Oakville, Burlington, Hamilton, St. Catharines, Niagara Falls, London and Peterborough. Availability for some locations depends on the service and scheduling. Check service areas or call +1 905-407-7353 to confirm your address.

Quote and booking

Book a heating or cooling visit

Share a few details and we will follow up. A written quote comes after a site review. There is no online checkout.

City and service type help us route your request
Urgency and property details let us prepare properly
Optional equipment photos speed up repairs and replacements

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Keep exploring

Build My QuoteList the equipment and services you need and request a quote after a site review.View page Ontario RebatesEligible Ontario customers may qualify for up to $7,500 depending on the program rules, equipment, property...View page Finance & WarrantiesFinancing, lease-to-own, rental, manufacturer warranty, labour warranty and extended warranty are six...View page