No overselling, no guesswork — just a Ac Repair crew that diagnoses it right the first time. Same-day appointments available across Addison 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 grew one honest service call at a time in communities like Addison. Our crews carry manufacturer certifications across the major residential and commercial equipment lines.
We're not interested in being the cheapest quote on the page — we're the team that shows up in the truck, not a subcontractor we've never met. We carry the credentials Addison inspectors and property managers expect to see, and we keep that documentation available on request for every job, big or small.
We know which neighborhoods run on older ductwork and which subdivisions were built with newer high-efficiency systems. 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.
Trust in this industry gets eroded fast, and it takes real consistency to earn it back. That's the gap we built Leonard HVAC to close. Every dispatcher, every technician, and every follow-up call is held to the same standard, because a customer who trusts us once tends to call us again — and Addison 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 Addison homes, and realistic scheduling given local demand. Our warranty and service history records stay attached to your address, so any future technician who visits already has the full picture.
We cover the full range of heating, cooling, and air quality work Addison properties actually need.
Breakdowns rarely happen at a convenient time, which is exactly why our emergency line runs 24 hours a day. Our Addison 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 Addison homes, which is exactly why most repairs don't require a return visit.

Not every repair call ends in a repair — sometimes the honest recommendation is a properly sized replacement. We walk Addison homeowners through load calculations so the new system is sized correctly for the actual square footage before a single piece of equipment gets ordered.
Most installs in Addison 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 light industrial and warehouse ventilation across Addison, with service agreements built around your operating hours.
Property managers working with multiple Addison locations can set up a standing account so every site gets consistent service history and pricing.

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 Addison 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.

Guarantees only mean something if a company actually honors them, so here's exactly what ours covers.
Details vary by job type and are always shared upfront, never buried in fine print.
We quote a flat rate before work begins and that number doesn't change once you approve it.
A technician doesn't consider the job done until the system is tested and performing correctly.
A little attention to how your system is running can save you a lot of money and discomfort.
A healthy system runs with a consistent, low hum — banging, screeching, or grinding usually points to a loose part or failing motor.
This is one of the most common complaints we hear on service calls across Addison.
A system working harder than it should to hit the same temperature shows up directly on your utility bill.
A system that won't hold a steady cycle is often fighting a sizing issue, a thermostat problem, or a refrigerant imbalance.
A burning smell should never be ignored — it can indicate an electrical issue that needs immediate attention.
We'll always tell you honestly when a repair is the better call versus when it isn't.
No inflated "emergency surcharge" games — the number we quote is the number you pay.
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.
Our techs recognize brand-specific quirks instead of learning your system on the job.
We explain what failed, why it failed, and what the options are.
Maintenance plan members get priority scheduling and discounted rates.
A snapshot of the feedback that keeps us accountable.
"The furnace stopped working overnight and someone was at our door before 9am. 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. Never once felt like I was being upsold on something I didn't need."
"Explained the sizing calculation so I understood why they weren't just installing the same unit again. Followed up a week later just to check everything was still running fine."
"Commercial dispatch was quick and the tech understood our system without needing to be walked through it. Kept our kitchen running through the weekend rush."
"The estimate matched the final invoice exactly, down to the dollar. My energy bill dropped noticeably the first month with the new system."
"Called at 11pm during a heat wave and honestly didn't expect anyone to pick up, let alone show up. This is the company I'm saving in my phone now."
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. 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.
Our technicians train across the major residential and commercial equipment lines, so you're not limited to a single brand's service network. 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 Addison 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.

Keeps the emergency truck stocked based on what actually fails most often locally.

Experienced with the light industrial and retail equipment common across the area.
For emergency no-heat or no-cool calls, we prioritize dispatch and aim to have a technician on-site the same day, often within a couple of hours.
Yes — every job gets a clear quote before any repair work begins, so there are no surprise line items on the invoice.
Our emergency line runs 24 hours a day, including nights, weekends, and holidays.
We maintain current credentials because it protects both our customers and our team.
We never push a replacement when a straightforward repair will genuinely solve the problem.
Ask your technician about current plan pricing during any service call.
Our dispatch area extends throughout the greater Addison region and nearby towns within Addison, IL.
Our commercial team handles rooftop units, multi-zone systems, and facility contracts alongside our standard residential repair work.
Yes, we service systems regardless of who originally installed them.
Ask about financing during your in-home estimate to see what fits your situation.
Systems that run harder due to heavy year-round use may benefit from more frequent check-ins.
If you smell gas or burning, shut off the system at the breaker and step outside, then call us immediately.
Ask about current after-hours rates when you call +1-866-805-8548.
Straightforward fixes like a capacitor swap or a thermostat replacement are often finished in well under an hour.
For most residential visits, yes, an adult should be present to grant access and approve any quoted work.
Housing stock varies a lot across Addison — older homes often still run original ductwork that needs different care than the sealed, high-efficiency systems going into newer builds.
We also work regularly with homeowners associations, property management companies, and multi-unit buildings throughout Addison.
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 Addison 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 Addison, IL and near Addison, 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.