Our Markham-based crews carry the parts and the know-how to get your air moving again today. Same-day appointments available across Markham and the surrounding zip codes.
Call +1-866-805-8548 and describe what your system is doing — the symptoms help us send a tech prepared with the right parts.
Ask as many questions as you want; we'd rather over-explain than leave you unsure.
Most repairs are completed same-visit, and we test the system before we leave to confirm it's actually holding.
Leonard HVAC was built by technicians who got tired of watching homeowners get oversold. Every technician we send to your door is background-checked, factory-trained, and licensed to work on the systems installed throughout Markham, IL.
You won't find us buried under layers of call-center scripts — we're the team that shows up in the truck, not a subcontractor we've never met. Licensing and insurance aren't optional line items for us, and we keep that documentation available on request for every job, big or small.
Being local matters more than most companies let on. That local knowledge shapes the parts we stock on the truck — it's the difference between a tech who's guessing and a tech who's seen your exact situation a hundred times before.
Ask around Markham and you'll hear the same complaint about a lot of HVAC companies. That's the gap we built Leonard HVAC to close. We track arrival windows, callback rates, and repeat-issue complaints internally so problems get caught before they become patterns, because a customer who trusts us once tends to call us again — and Markham is a small enough community that reputation travels fast.
When you call +1-866-805-8548, you're talking to someone who understands the local permitting process, the common equipment brands installed in Markham homes, and realistic scheduling given local demand. It also means faster escalation when something's urgent — a local dispatcher can reroute the nearest truck in minutes, not hours.
Whether it's a mid-summer breakdown or a planned system replacement, our Markham techs handle it with the same level of care.
Breakdowns rarely happen at a convenient time, which is exactly why our emergency line runs 24 hours a day. Our Markham dispatch team moves emergency tickets to the front of the schedule so a technician is diagnosing your system as fast as physically possible.
We keep the truck stocked with the parts that fail most often on the equipment common to Markham homes, which is exactly why most repairs don't require a return visit.
An aging system that's constantly breaking down usually costs more to keep patching than to replace. We walk Markham homeowners through financing and rebate options where available before a single piece of equipment gets ordered.
Most installs in Markham are completed in a single day, and we walk you through the new thermostat and any app controls before we leave.
Downtime in a commercial space costs money every hour a system is offline. Our commercial division services multi-zone commercial buildouts across Markham, with after-hours work to avoid disrupting business.
Our commercial techs are trained to work around your customers and staff, scheduling noisy or disruptive work outside peak hours whenever possible.
A seasonal tune-up catches the kind of wear that turns into a mid-summer no-cool call. Beyond standard tune-ups, we also handle humidifier, dehumidifier, and air purifier installation for Markham households that want more than just temperature control.
Maintenance plan members in Markham get scheduling reminders automatically, so tune-ups don't fall through the cracks during a busy season.
Guarantees only mean something if a company actually honors them, so here's exactly what ours covers.
Every repair comes with a workmanship warranty explained in plain terms before we leave.
We quote a flat rate before work begins and that number doesn't change once you approve it.
Our office follows up after major repairs and installs to confirm everything is holding.
Most breakdowns don't happen without warning — they announce themselves for weeks before the system actually quits.
A healthy system runs with a consistent, low hum — banging, screeching, or grinding usually points to a loose part or failing motor.
Weak airflow from the vents often traces back to a clogged filter, a failing blower motor, or leaking ductwork.
Gradual efficiency loss is easy to miss month to month, but it adds up fast over a season.
Short cycling puts extra wear on the compressor and shortens the system's overall lifespan.
A burning smell should never be ignored — it can indicate an electrical issue that needs immediate attention.
Repeated repairs on an aging system are usually the clearest sign that replacement will save more money than another patch job.
We explain diagnostic fees and repair estimates before authorizing work.
Dispatchers give you a realistic arrival window instead of a vague "sometime today".
We don't consider a job finished until the system is actually performing correctly.
Every technician carries current state licensing and manufacturer training.
Photos and plain-language notes accompany every diagnostic.
Replacement systems don't have to be paid in one lump sum.
Every review below reflects an actual service call in the Markham area.
"The furnace stopped working overnight and someone was at our door before 9am. Fixed on the first visit and explained everything in terms I could actually understand."
"Scheduled a fall tune-up and they caught a cracked part before it became a real problem. Techs are always polite, always on time, and clean up after themselves."
"Had a full system replacement done and it was the smoothest home project I've had in years. Followed up a week later just to check everything was still running fine."
"As a property manager, having a company that actually answers after-hours calls is rare. Kept our kitchen running through the weekend rush."
"I appreciated that they didn't try to sell me a bigger unit than I needed. Installation crew was in and out in a day and left the space cleaner than they found it."
"Diagnosed a failed capacitor and had it swapped within the hour. No overnight surcharge shock — the price matched what dispatch quoted me on the phone."
Understanding what typically fails helps homeowners know what to watch for and when a repair call is worth making before things get worse.
Homeowners who schedule a tune-up ahead of each season tend to call us far less often for emergency repairs. Before the coldest stretch of the year, a heating system benefits from a full safety inspection, checking the heat exchanger, ignition system, and airflow to catch any issue that could turn into a no-heat emergency.
Clearing debris, leaves, and overgrown landscaping away from an outdoor condenser unit gives it room to breathe and keeps it running efficiently. None of this replaces a professional tune-up, but it does reduce the wear that leads to premature breakdowns between visits.
We also service package units common on manufactured and modular homes throughout the Markham area. If your system was installed by a different company entirely, that's not a problem — we service equipment regardless of who originally put it in, and we'll pull the model and serial information to confirm parts compatibility before any repair begins.
Every tech on our Markham roster goes through background checks, licensing verification, and ongoing manufacturer training.
Over a decade in residential heating and cooling, with a focus on load calculations and full system replacements.
Known for fast, accurate diagnostics on no-heat and no-cool breakdowns.
Experienced with the light industrial and retail equipment common across the area.
Because our trucks are staged near Markham, average arrival windows run faster than what national chains typically offer.
We explain the diagnostic fee upfront and provide a flat-rate repair quote once the issue is identified.
Yes, no-heat and no-cool situations are treated as priority calls regardless of the hour.
Yes — licensing and insurance documentation is available on request for any job, residential or commercial.
As a general guideline, if a system is past 12-15 years old and facing a costly repair, replacement often makes more financial sense.
Plan members typically see fewer surprise breakdowns because small issues get caught during routine visits.
We cover Markham and the surrounding communities, including the zip codes listed in our coverage section below.
Property managers and business owners can request a dedicated point of contact for ongoing service.
If parts require special ordering for a less common brand, we'll communicate that timeline upfront.
Ask about financing during your in-home estimate to see what fits your situation.
Most Markham homes benefit from two tune-ups a year — one before cooling season and one before heating season.
If you smell gas or burning, shut off the system at the breaker and step outside, then call us immediately.
Our pricing is explained clearly before dispatch, and any after-hours consideration is communicated upfront — never as a surprise on the final invoice.
Straightforward fixes like a capacitor swap or a thermostat replacement are often finished in well under an hour.
For commercial accounts or rental properties, a designated point of contact or property manager can coordinate access instead.
From the older, established streets near the center of Markham to the newer developments on the outskirts, our trucks cover the full footprint of the city.
If you manage several units or a shared system across a Markham property, ask about setting up a standing service account so every request gets handled under one consistent agreement.
A full system replacement is one of the bigger home expenses most people face, and we don't expect everyone to pay it in a single lump sum. If a rebate or local incentive program applies to your Markham installation, our technicians will flag it during the estimate rather than leaving you to track it down after the fact.
We dispatch throughout Markham and the neighboring communities, keeping response times tight because our trucks stay close to home.
Property managers with multiple Markham addresses can consolidate everything under one account for simpler scheduling and consistent pricing across every location.
