We fix what's broken, fast, and we don't disappear after the invoice. Emergency dispatch available across Londonderry 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.
A licensed technician arrives, runs a full diagnostic, and explains exactly what's wrong in plain language.
If anything feels off after we leave, a follow-up call gets a technician back out to make it right.
Leonard HVAC didn't start as a franchise chasing volume. We invest in ongoing training so our techs recognize a failing capacitor, a cracked heat exchanger, or a refrigerant leak before it turns into an emergency.
We're not the biggest name in Londonderry — we're the crew that answers the phone at 2am when your furnace quits in the middle of a cold snap. 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, big or small.
Londonderry's climate swings hard, and generic national playbooks don't always fit. That local knowledge shapes the maintenance schedules we recommend — 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. 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 Londonderry 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 Londonderry 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 Londonderry dispatch team prioritizes no-heat and no-cooling calls so a technician is diagnosing your system as fast as physically possible.
If a specialty part genuinely does need to be ordered, we'll set up a safe temporary fix and give you a real timeline instead of leaving you guessing.

If your unit is past its expected service life, running loud, or spiking your utility bill, a replacement conversation is worth having. We walk Londonderry homeowners through efficiency ratings and how they translate into real monthly savings before a single piece of equipment gets ordered.
Most installs in Londonderry 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 Londonderry, with after-hours work to avoid disrupting business.
Property managers working with multiple Londonderry 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 duct cleaning and sealing to stop conditioned air from leaking into attics and crawlspaces for Londonderry 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 Londonderry technician on our team is held to.
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.
Our office follows up after major repairs and installs to confirm everything is holding.
Catching these signs early usually means a same-day repair instead of an emergency call at the worst possible moment.
Ignoring new noises is one of the fastest ways to turn a small repair into a major one.
If some rooms stay hot or cold no matter what the thermostat says, the system may be struggling to distribute air evenly.
A system working harder than it should to hit the same temperature shows up directly on your utility bill.
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.
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.
Our techs recognize brand-specific quirks instead of learning your system on the job.
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 Londonderry area.
"I called three other companies first and this was the only one that actually picked up. 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. Never once felt like I was being upsold on something I didn't need."
"Had a full system replacement done and it was the smoothest home project I've had in years. New system is noticeably quieter and our energy bill actually dropped."
"Commercial dispatch was quick and the tech understood our system without needing to be walked through it. Now our go-to for every property in the portfolio."
"I appreciated that they didn't try to sell me a bigger unit than I needed. My energy bill dropped noticeably the first month with the new system."
"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.
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.
We also service package units common on manufactured and modular homes throughout the Londonderry 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.
Here's a look at the kind of experience that shows up at your door.

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.

Focuses on commercial rooftop units, multi-zone systems, and facility maintenance contracts.
Standard appointments are usually scheduled within 24-48 hours, while true emergencies jump the queue.
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.
We never push a replacement when a straightforward repair will genuinely solve the problem.
Yes, our maintenance plans include seasonal tune-ups, priority scheduling, and discounted repair rates for members.
If you're unsure whether your address falls in our service area, a quick call to +1-866-805-8548 will confirm it.
Our commercial team handles rooftop units, multi-zone systems, and facility contracts alongside our standard residential repair work.
Our technicians are trained across the major residential and commercial equipment lines, not limited to a single manufacturer.
Financing options are available for qualifying replacement installations, and our team can walk you through what's currently offered.
Most Londonderry homes benefit from two tune-ups a year — one before cooling season and one before heating season.
Check that the thermostat has power and the batteries aren't dead, and check your breaker panel for a tripped switch before calling.
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 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 Londonderry 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 Londonderry 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 Londonderry installation, our technicians will flag it during the estimate rather than leaving you to track it down after the fact.
We dispatch throughout Londonderry and the neighboring communities, keeping response times tight because our trucks stay close to home.
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.