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.
No automated menus for emergencies — a real person handles the call.
A licensed technician arrives, runs a full diagnostic, and explains exactly what's wrong in plain language.
Most repairs are completed same-visit, and we test the system before we leave to confirm it's actually holding.
Leonard HVAC didn't start as a franchise chasing volume. Every technician we send to your door is background-checked, factory-trained, and licensed to work on the systems installed throughout Markham, IL.
We're not the biggest name in Markham — we're the company that tells you what actually needs fixing instead of what pads the ticket. We carry the credentials Markham inspectors and property managers expect to see, and we keep that documentation available on request for every job, big or small.
Markham's climate swings hard, and generic national playbooks don't always fit. That local knowledge shapes how we diagnose problems — 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.
Every service below is backed by the same licensing, warranty, and upfront pricing you get on any job we run.
Breakdowns rarely happen at a convenient time, which is exactly why our emergency line runs 24 hours a day. Our Markham dispatch team sends the closest available truck first 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 load calculations so the new system is sized correctly for the actual square footage before a single piece of equipment gets ordered.
Every install ends with a performance test, confirming airflow, temperature split, and refrigerant charge are all where they should be before we consider the job finished.
Downtime in a commercial space costs money every hour a system is offline. Our commercial division services multi-zone commercial buildouts across Markham, with service agreements built around your operating hours.
Property managers working with multiple Markham locations can set up a standing account so every site gets consistent service history and pricing.
Most emergency breakdowns start as a small, ignorable warning sign months earlier. Beyond standard tune-ups, we also handle indoor air quality upgrades for homes with allergy or asthma concerns for Markham households that want more than just temperature control.
We'll show you photos of anything concerning we find, along with a plain-language explanation of what it means and whether it's urgent.
We'd rather set clear expectations upfront than make vague promises we can't back up.
If the same issue returns within the warranty period, we come back and fix it at no additional labor cost.
If a competitor's written quote for the same scope of work is genuinely lower, ask us about it.
A technician doesn't consider the job done until the system is tested and performing correctly.
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.
If some rooms stay hot or cold no matter what the thermostat says, the system may be struggling to distribute air evenly.
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 musty smell often points to mold or moisture buildup somewhere in the ductwork.
If you're calling about the same problem every few months, the underlying cause likely hasn't been fully addressed.
You'll know the cost before a wrench touches your system.
Because our trucks are stationed near Markham, we're rarely far from your address.
If something isn't right after we leave, we come back and make it right.
Every technician carries current state licensing and manufacturer training.
Photos and plain-language notes accompany every diagnostic.
We'll walk you through what's actually available before you decide.
We don't write these — our customers do.
"I called three other companies first and this was the only one that actually picked up. No pressure to buy a whole new system when a repair was all we needed."
"Scheduled a fall tune-up and they caught a cracked part before it became a real problem. You can tell these guys actually know what they're doing."
"Explained the sizing calculation so I understood why they weren't just installing the same unit again. New system is noticeably quieter and our energy bill actually dropped."
"As a property manager, having a company that actually answers after-hours calls is rare. Kept our kitchen running through the weekend rush."
"Got quotes from four different companies for a replacement and this was the only one that actually walked me through the load calculation. Would use them again without hesitation."
"Called at 11pm during a heat wave and honestly didn't expect anyone to pick up, let alone show up. Genuinely relieved to have found a crew that answers when it matters."
None of these are unusual or embarrassing — they're just the normal wear and tear that comes with running a system through Markham's seasonal swings.
Markham's seasonal swings put real stress on a system that isn't maintained regularly. Filters should be checked monthly during heavy-use seasons and replaced roughly every 60-90 days depending on your household and any pets.
Setting a programmable or smart thermostat to a consistent schedule reduces the number of times the system has to work hard to catch up to a big temperature swing. None of this replaces a professional tune-up, but it does reduce the wear that leads to premature breakdowns between visits.
Whether your Markham home has a traditional split system, a ductless mini-split, a heat pump, or a hybrid dual-fuel setup, our crews are equipped to diagnose and repair it. 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.
Here's a look at the kind of experience that shows up at your door.
Manufacturer-certified across multiple major residential equipment lines.
Runs point on overnight and weekend emergency calls throughout Markham.
Works directly with Markham property managers to schedule around business hours.
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.
Every technician we send is licensed in accordance with Markham, IL requirements and carries full liability coverage.
As a general guideline, if a system is past 12-15 years old and facing a costly repair, replacement often makes more financial sense.
Yes, our maintenance plans include seasonal tune-ups, priority scheduling, and discounted repair rates for members.
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.
Yes, we service systems regardless of who originally installed them.
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.
Beyond basic safety checks, it's best to leave diagnosis to a licensed technician rather than attempting a repair yourself.
Our pricing is explained clearly before dispatch, and any after-hours consideration is communicated upfront — never as a surprise on the final invoice.
More involved repairs, like a coil replacement or a refrigerant leak repair, take longer and the tech will give you a realistic estimate before starting.
Let dispatch know ahead of time if access will be handled differently than a standard homeowner visit.
Our technicians are familiar with both, which means less time spent figuring out your specific setup and more time actually fixing the problem.
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.
We accept standard payment methods for repairs and smaller jobs, and we'll always tell you upfront what a given service is likely to cost so there's no last-minute scramble to figure out payment. 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.
If your address falls within Markham, IL and near Markham, there's a strong chance we already service your street.
If you're on the edge of our listed zip codes, it's still worth a call, since routes and coverage get adjusted as demand shifts.
