Mitsubishi Diamond Contractor · EPA Certified

Air Conditioning & Heat Pump Services

Central air, ductless mini-splits, and cold-climate heat pumps—repaired, maintained, and installed by an EPA-certified team. As a Mitsubishi Diamond Contractor, we install and service the ductless systems that work best in older South Shore homes.

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Cooling Services

Comfortable Through August

AC Repair

Not cooling, frozen coils, refrigerant leaks, and electrical faults—diagnosed properly, not just topped off.

Central AC Installation

Condensers, coils, and air handlers sized to the house with a real load calculation.

AC Maintenance & Tune-Ups

Spring tune-ups that catch refrigerant and airflow problems before the first heat wave.

Ductless Mini-Splits

Mitsubishi and Fujitsu systems for homes without ductwork, additions, and problem rooms.

Heat Pumps

Cold-climate heat pumps that heat and cool—the equipment carrying the largest Mass Save incentives.

Indoor Air Quality

Filtration, humidity control, and ventilation for allergies, dust, and musty basements.

Fix the AC or Replace It? The R-410A Factor

If your AC or heat pump was installed before 2025, it almost certainly runs on R-410A — a refrigerant now being phased out. New equipment no longer uses it, and both the refrigerant and repair parts get scarcer and more expensive every season. That shifts the repair-or-replace math, and the calculator below is weighted to reflect it.

3R Plumbing & Mechanical

Repair it or replace it?

Pick your system, set two sliders. We use the industry “$5,000 rule” — age times repair quote — and we lean harder toward replacement on older AC and heat pump systems now that R-410A equipment is no longer made and parts are getting scarce.

How old is the system? Check the data plate — AC and heat pumps often last 10–15 years, furnaces and boilers 15–20.

10 years

What’s the repair quote? The estimate you’ve been given — or your best guess for the fix.

$600

10 yrs × $600= $6,000

Repair

Replace

$3,000$4,000

Our read

—

Call (781) 974-5239 — we’ll give you both numbers

Verdicts follow the $5,000 rule, weighted toward replacement — heavier on AC and heat pumps, since R-410A equipment is no longer manufactured and refrigerant and parts supply keeps shrinking. It’s a rule of thumb, not a diagnosis — refrigerant type, efficiency, repair history, and Mass Save rebates on high-efficiency replacements all move the answer. We’ll always quote the repair and the replacement so you can decide with real numbers.

Why Ductless Works So Well Here

A lot of South Shore housing stock predates central air entirely—antique colonials in Hingham and Duxbury, capes and ranches built for a single oil boiler, and coastal cottages that were never insulated for year-round living. Running new ductwork through those homes is invasive, expensive, and sometimes impossible.

Ductless mini-splits solve that. Each indoor head is zoned independently, so the third-floor bedroom that has always been ten degrees hotter finally has its own control. Modern cold-climate units keep producing heat well below freezing, which means one system covers both summer cooling and most of your winter heating load.

A note for coastal homeowners. In Hull, Scituate, Marshfield, Cohasset, and the waterfront sections of Duxbury, salt air is hard on outdoor condensers. Placement matters, coated coils are worth specifying, and an annual rinse extends equipment life significantly. We factor that into every coastal installation rather than treating it like an inland job.

Ready to be comfortable?

Free in-home estimates on new cooling and heat pump systems.

Call (781) 974-5239

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