Straight answers on AC and heat, from the contractor who does the work

The residential diagnostic is $129, and it is waived if you approve a recommended repair over $250. Commercial is $149, waived on repairs over $300. You get the diagnostic price on the phone before anyone is dispatched, and the repair price in writing before any work starts.

Mon–Sat, 8:00 AM – 8:00 PM. You can call (904) 467-1100, book online, or request a callback through the contact page. Calls are answered by the owner, not a call center.

8 Northeast Florida counties: Duval, Clay, St. Johns, Nassau, Baker, Bradford, Putnam, Flagler. Jacksonville and the Westside are the home turf, so same-day and next-morning appointments are realistic there. Outlying markets are scheduled, and you will be told which applies to your address rather than promised a window nobody can keep.

Call (904) 467-1100, book online, or use the callback form on the contact page. Booking online is the fastest option outside of business hours.

Yes, for system replacements, through Synchrony, GreenSky, Wisetack, or your own credit union's home-improvement loan. The lender sets approval, rates, and terms — not us. See the financing page for how the process works and what to compare before you sign.

Military members, first responders, and seniors get 10% off residential service. Mention it when you book — it cannot be applied retroactively after an invoice is closed. The diagnostic fee is also waived on recommended repairs over $250.

It depends on what failed, not on age alone. A capacitor or contactor is worth fixing on almost any system. A failed compressor or leaking evaporator coil on an older unit usually is not. Refrigerant type matters too — an R-22 system with a leak is normally a replacement candidate. You get the arithmetic for both paths in writing and you decide.

Usually about 10 to 15 years here. Our systems run far more hours per year than most of the country, humidity keeps the coil and drain pan permanently wet, and coastal salt air corrodes outdoor coils faster. Maintenance, correct sizing, and installation quality account for most of the spread within that range.

Twice a year in this climate — once before cooling season and once in the fall. Heat pumps run year round and benefit most from both visits. Most manufacturer warranties also require documented annual service to stay valid.

Usually the opposite. An oversized system reaches setpoint fast, shuts off, and never runs long enough to pull moisture out of the air. That is the classic cause of a Florida house that is cold and clammy at the same time. Sizing should come from a Manual J load calculation on your specific house.

Your air conditioner removes moisture as a side effect of cooling, and that process needs runtime. Oversized equipment or restricted airflow leaves the house cool but damp. Target 45–55% relative humidity indoors; above about 60% is where musty smells, dust mites, and mold risk start.

Check the thermostat fan setting first. Fan set to ON keeps blowing air across a wet coil after the compressor stops, re-evaporating that moisture back into the house. Set it to AUTO. If it is still humid, the likely causes are oversizing, leaking return duct in the attic, low refrigerant charge, or a dirty coil.

Spaces the ductwork was never going to reach properly — garage conversions, additions, sunrooms, bonus rooms over the garage, and detached offices. Each indoor head has its own control, so that space stops dragging the rest of the house off balance.

For scheduling and phone control, yes. Two cautions: it has to be compatible with your equipment — particularly heat pumps with backup heat strips — and many models need a common (C) wire. A thermostat configured for a furnace instead of a heat pump can run expensive resistance heat all season without you noticing.

U.S. production and import of R-22 ended in 2020, so the only supply remaining is recovered, recycled, or previously stockpiled. Recharging after a leak is expensive and gets more so. An R-22 system that develops a leak is usually better replaced than repeatedly recharged.

R-410A was the standard for about two decades. Under EPA rules phasing down high-GWP refrigerants, new residential systems are moving to lower-impact alternatives such as R-454B and R-32. These are A2L-classified, which changes handling and equipment requirements but not how the system works for you.

Yes, comfortably. Heat pumps handle mild winters well, and backup heat strips cover the coldest mornings. Air from a heat pump feels cooler at the vent than furnace air — that is normal, not a fault.

That is almost always the defrost cycle clearing frost off the outdoor coil, and it is supposed to happen. Steam and a brief whoosh are normal. If the unit stays encased in ice rather than clearing, that is worth a service call.

The coil is running colder than it should, from either restricted airflow or low refrigerant charge. Turn cooling off, set the fan to ON to thaw it, and never chip at the ice — the coil is thin aluminum and copper. If it refreezes after a clean filter, it needs the charge checked properly.

Nearly always a clogged condensate drain line — algae and sludge grow in that warm, damp pipe. Most systems have a float switch that shuts cooling off when the drain backs up, which is why a water problem often shows up as 'the AC just stopped.' Clearing and treating the line fixes it.

Check it monthly. A standard 1-inch filter usually needs replacing every one to three months — sooner with pets, during pollen season, or while remodeling. A clogged filter is the single most common cause of a frozen coil.

Check that the thermostat is set to COOL with the fan on AUTO, inspect the filter, and check both breakers — most systems have separate indoor and outdoor circuits, and a tripped outdoor breaker leaves the blower running while nothing gets cooled. Then look at the outdoor unit: the fan should be spinning and the air leaving it should feel warm.

Yes — walk-in coolers and freezers, reach-ins, prep tables, and ice machines. The commercial diagnostic is $149, waived on repairs over $300. Calls with product at risk are prioritized.

Yes, and it is a core part of the business rather than a sideline. That includes scheduling directly with tenants, make-ready turnovers, and per-unit HVAC inspection forms. Langston's is a member of the First Coast Apartment Association.

Yes. You get a written condition report covering equipment age, refrigerant type, and the measured readings — temperature split, static pressure, pressures, and amp draw. Langston's is a JAXREIA member and does this work regularly for buyers and investors.

Yes. Florida Certified Mechanical Contractor license CMC1251311, licensed and insured. You can verify any Florida contractor's license yourself through the Department of Business and Professional Regulation, and you should — for us or anyone else quoting your job.

Federal law requires anyone handling refrigerant to hold EPA Section 608 certification. Universal certification covers all equipment types, including the commercial refrigeration side. It is a legal requirement, not a marketing badge — ask any contractor who will be opening a sealed system.

Yes. A system change-out is permitted mechanical work in Northeast Florida, and the licensed contractor pulls it. The inspection verifies the electrical, the condensate safety, and that the equipment installed matches what was permitted. Unpermitted work tends to surface at closing when you sell.