Our Altadena-based crews carry the parts and the know-how to get your air moving again today. Same-day appointments available across Altadena 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.
You'll get a flat-rate quote before any repair work begins — no guessing what the final bill will look like.
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. Our crews carry manufacturer certifications across the major residential and commercial equipment lines.
We're not the biggest name in Altadena — we're the team that shows up in the truck, not a subcontractor we've never met. Every job we run is backed by full liability coverage and current state licensing, and we keep that documentation available on request for every job, residential or commercial.
Altadena'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.
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 Altadena is a small enough community that reputation travels fast.
That local context saves time on every call, because we're not starting from zero on basic questions about your neighborhood or your system. We keep parts inventory stocked based on what actually fails most often on Altadena's housing stock.
We cover the full range of heating, cooling, and air quality work Altadena properties actually need.
Breakdowns rarely happen at a convenient time, which is exactly why our emergency line runs 24 hours a day. Our Altadena 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 Altadena 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 Altadena 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 Altadena 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 Altadena, with priority response for facilities that can't afford downtime.
Our commercial techs are trained to work around your customers and staff, scheduling noisy or disruptive work outside peak hours whenever possible.

Most emergency breakdowns start as a small, ignorable warning sign months earlier. Beyond standard tune-ups, we also handle duct cleaning and sealing to stop conditioned air from leaking into attics and crawlspaces for Altadena 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.

This is the standard every Altadena technician on our team is held to.
Every repair comes with a workmanship warranty explained in plain terms before we leave.
Emergency dispatch never comes with a hidden surcharge sprung on you after the fact.
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.
Ignoring new noises is one of the fastest ways to turn a small repair into a major one.
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 musty smell often points to mold or moisture buildup somewhere in the ductwork.
We'll always tell you honestly when a repair is the better call versus when it isn't.
We explain diagnostic fees and repair estimates before authorizing work.
Dispatchers give you a realistic arrival window instead of a vague "sometime today".
Parts and labor are backed by warranty terms explained in plain language.
We run background checks because you're letting someone into your home.
You make the final call — we just make sure you have the full picture.
Maintenance plan members get priority scheduling and discounted rates.
We don't write these — our customers do.
"Our AC quit on the hottest weekend of the year and they had a tech out within a couple of hours. Fixed on the first visit and explained everything in terms I could actually understand."
"Signed up for the annual plan after our first repair and it's paid for itself already. 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."
"As a property manager, having a company that actually answers after-hours calls is rare. Documentation for our records was thorough and easy to file."
"Got quotes from four different companies for a replacement and this was the only one that actually walked me through the load calculation. 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. Genuinely relieved to have found a crew that answers when it matters."
Understanding what typically fails helps homeowners know what to watch for and when a repair call is worth making before things get worse.
Altadena's seasonal swings put real stress on a system that isn't maintained regularly. Before the heaviest cooling months hit, it's worth having the refrigerant charge checked, the condenser coils cleaned, and the filter replaced — all of which directly affect how hard the compressor has to work.
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.
Whether your Altadena 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.

Handles the majority of Altadena installs and specializes in properly sizing equipment for older housing stock.

Runs point on overnight and weekend emergency calls throughout Altadena.

Works directly with Altadena property managers to schedule around business hours.
Standard appointments are usually scheduled within 24-48 hours, while true emergencies jump the queue.
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.
Yes — licensing and insurance documentation is available on request for any job, residential or commercial.
We never push a replacement when a straightforward repair will genuinely solve the problem.
Plan members typically see fewer surprise breakdowns because small issues get caught during routine visits.
We cover Altadena 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.
Twice-yearly maintenance is the standard we recommend given the temperature swings the area sees.
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.
Most standard repairs are completed in under two hours once the technician has diagnosed the issue and you've approved the quote.
For most residential visits, yes, an adult should be present to grant access and approve any quoted work.
From the older, established streets near the center of Altadena 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 Altadena 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 Altadena installation, our technicians will flag it during the estimate rather than leaving you to track it down after the fact.
Coverage extends across Altadena proper and into the nearby zip codes listed below.
Property managers with multiple Altadena addresses can consolidate everything under one account for simpler scheduling and consistent pricing across every location.