Seasonal tune-up and full diagnostic on your Carrier, Trane, or Goodman system - readings shown to you before any repair is proposed
Diagnosis first, numbers second - you approve the repair price before a single part goes in.
HVAC Company in Lexington, MA
Lexington homeowners typically spend $150-$700 on HVAC repairs and $3,500-$7,500 on AC installation, with most repair calls completed same-day. Coldharbour Heating & Air dispatches crews locally from our Boston-area office, and our technicians are specifically trained for the retrofit challenges that define this market: engineering ductless and heat-pump solutions into hydronic-only homes built during the Route 128 boom. If you need help now, call us at (817) 402-2972 – a live person answers 24 hours a day.
Why Lexington Homes Are Different
Lexington’s housing stock is dominated by garrison colonials, raised ranches, and split-levels thrown up fast between 1950 and 1975 to feed the tech-corridor migration. Most were built with oil-fired cast-iron boilers and baseboard or steam heat – no ductwork, no central air, no infrastructure for the forced-air systems that HVAC contractors in other suburbs take for granted.
That missing ductwork is the central engineering puzzle we solve. When a Lexington homeowner wants cooling, or when they’re converting to a heat pump to capture Mass Save rebates, we’re not swapping like for like. We’re designing ductless mini-split zones or new-duct retrofits into floor plans that were never drawn for it. The Battle Green historic district adds another layer: homes there fall under Lexington Historical Commission review for exterior alterations visible from public ways. We’ve learned to pre-photograph proposed condenser placements and file proactively, because a stop-work order on a mini-split install is expensive for everyone.
Climate matters too. Lexington sits far enough inland to lose Boston Harbor’s moderating effect. Our design heating loads target -5°F to 0°F outdoor conditions, which means cold-climate heat pump selection and documented low-ambient performance aren’t marketing points here – they’re load-calculation requirements. Summer humidity in the older, leakier stock makes latent-capacity sizing equally critical. Coastal contractors who size by rule of thumb get callbacks we don’t.
Our Main Lexington Services
Most calls we get from Lexington fall into three categories: cooling repair when the humidity spikes, heating repair when the boiler quits in a cold snap, and installation when homeowners are ready to add air conditioning or convert to electric heat.
AC Repair in Lexington
AC repair in Lexington usually means a ductless mini-split or a small add-on system rather than central air, because so many homes here never had ducts to begin with. We see refrigerant leaks from vibration-worn flare connections on line sets that run through tight colonial framing, and we see compressor strain from undersized units fighting 85°F-plus days with high latent loads. Our trucks carry flare tools, vacuum pumps, and replacement heads for the major ductless brands, and we issue a written 365-Day Done Right Promise on every repair. AC Repair in Lexington

Furnace Repair in Lexington
When Lexington homeowners say “furnace,” they often mean an oil-fired boiler with cast-iron baseboard or old steam radiators. We service the full hydronic stack: burner nozzles, circulator pumps, zone valves, expansion tanks, and the controls that tie them together. Igniter failures, aquastat faults, and sediment-choked boiler sections are common in units pushing 30-plus years. We stock nozzles, pump cartridges, and common control boards for brands including Rheem and York, and we explain every finding before we quote the fix. Furnace Repair in Lexington

AC Installation in Lexington
AC installation in Lexington is almost always a retrofit into a home with no existing ductwork. We design ductless multi-zone systems or, where framing allows, low-profile ducted solutions for whole-house cooling. The Mass Save heat-pump rebates have made cold-climate mini-splits the dominant choice here, but proper sizing matters: too small and the unit can’t handle the humidity or the design-day cold; too large and it short-cycles, wastes energy, and fails to dehumidify. We perform a Manual J load calculation, specify equipment with documented low-ambient capacity, and provide a fixed written price before any work begins. AC Installation in Lexington

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Lexington
Our technicians train on nine major residential HVAC brands: Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. We stock common capacitors, contactors, igniters, and control boards for our brands locally, which means most Lexington repairs don’t wait for a parts run.
Pricing for HVAC Company in Lexington, MA
| Service | Typical Range in Lexington |
|---|---|
| AC Repair – minor (capacitor, contactor, control reset) | $150-$350 |
| AC Repair – moderate (refrigerant leak repair, blower motor) | $350-$500 |
| AC Repair – major (compressor diagnosis, coil replacement) | $500-$650 |
| Furnace Repair – minor (igniter, flame sensor, thermostat) | $150-$300 |
| Furnace Repair – moderate (circulator pump, zone valve) | $300-$500 |
| Furnace Repair – major (boiler section, control replacement) | $500-$700 |
| AC Installation – ductless mini-split, single zone | $3,500-$5,000 |
| AC Installation – ductless multi-zone or low-profile ducted | $5,000-$7,500 |
| Annual Tune-Up (heating or cooling system) | $80-$200 |
Lexington prices run toward the higher end of our ranges when we need engineered line-set routing through tight colonial framing, or when Historical Commission review requires revised placement drawings. What doesn’t change is our upfront-price rule: we hand you a written price before any tool comes out, and that number is firm.
Neighborhoods We Serve in Lexington
We cover all of Lexington, from the historic core to the postwar subdivisions. Most calls in this compact town see us arriving within our stated window, with scheduling coordinated from our Boston office.
- Centre (Battle Green historic district)
- East Lexington
- Lexington Heights
- Meriam Hill
- Pine Hill
Service Area – Cities Near Lexington
Our crews work throughout the Route 128 corridor. We regularly take calls from Woburn, MA to the north, Burlington, MA to the northeast, and we also serve Winchester, CA and Arlington, WA within our extended service network. If you’re unsure whether your address falls in our coverage, call us and we’ll confirm directly.
Serving Lexington, MA - Our Local Coverage Area
We’re based in the Lexington area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About HVAC Company in Lexington
Most Lexington repair calls are scheduled same-day or next-day, with true no-heat or no-cooling emergencies prioritized. Our phones are answered by a live person 24/7, so you’ll know your arrival window before you hang up. Call (817) 402-2972 to check today’s availability.
If your home is in the Centre district near Battle Green and the condenser will be visible from a public way, yes – exterior alterations may require review. We pre-photograph proposed placements and file proactively to avoid stop-work delays. Homes outside the historic district typically proceed without this step.
Yes – Lexington’s high electrification demand is partly driven by strong Mass Save rebate programs for cold-climate heat pumps. We handle the rebate paperwork as part of our installation process and specify equipment that meets program requirements. Ask about current rebate levels when you call for your written estimate.
Ready to schedule? Call Coldharbour Heating & Air at (817) 402-2972 for a free estimate. A live person will answer, we’ll give you a firm arrival window, and you’ll get a written price before any work begins – guaranteed.
What happens when you call
- 1A real person answersNo phone trees - talk to a local hvac pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Lexington Customers Say
"The repair was done well and quickly. Scheduling over the phone was a little clunky and I got transferred twice, but the tech himself was great and on time."
- Brett Haygood"Furnace was short cycling all winter. They diagnosed a bad sensor instead of condemning the whole unit like I feared. Cheap fix, honest call."
- Russ Tiedemann"Thermostat and a weak blower. Fixed both in one visit, explained the guarantee, and didn't leave a mess. I've already recommended them to my neighbor."
- Natalie Esposito







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