Cohasset · Air Conditioning
Central air not cooling in your Cohasset home, or a condenser showing salt and age? See what to check first, then call to reach an independent local HVAC contractor.
Cohasset, Massachusetts
An outdoor condenser in Cohasset lives a harder life than one inland. Salt carried on the onshore breeze settles on aluminum fins and copper tubing, and in the parts of town near the harbor and the cove, storm flooding is a real threat to anything mounted near the ground. A February 2025 Metropolitan Area Planning Council memo notes the town has identified 166 coastal flooding pathways.
That doesn't mean every Cohasset AC failure is about the ocean. Many come down to the usual suspects: a clogged filter, a frozen evaporator coil, a failed capacitor, a tripped float switch on the condensate line, or low refrigerant from a slow leak. A few quick checks can tell you whether the problem is simple or needs a technician.
This page also covers replacement, including whether a heat pump makes more sense than a new air-only system. A call or online request connects you with an independent cooling contractor who serves Cohasset.
Frost on the larger copper line usually means low airflow or low refrigerant. Turn the cooling off and let it thaw before the technician arrives.
A chalky film or flaking fins on a condenser near the water signal salt corrosion, which cuts efficiency and eventually causes leaks.
A humming condenser with a still fan often has a failed capacitor or motor. Shut it off so the compressor isn't strained.
Drips from an attic air handler or a ceiling stain below it point to a clogged condensate drain or a full overflow pan.
Local knowledge
The shoreline and summer water rules both touch how you care for an AC system here.
Harbor Flooding
The town held Cohasset Harbor climate resilience forums in 2022 and a public forum on harbor flooding concepts on May 1, 2025. If your condenser sits low near the harbor, ask about raising it on a taller pad or wall bracket when it's next serviced or replaced.
Source: Town of Cohasset (archived page)
Summer Water Limits
The Cohasset Water Department issued a Drought Watch on July 1, 2026 and eased it to an advisory on August 1, and on June 16, 2026 the Weir River Water System banned outdoor water use in North Cohasset. Rinsing salt off condenser coils uses outdoor water, so check current restrictions or ask the technician to clean the coils during service.
Source: Cohasset Water Department
Power Supply
Cohasset's electricity comes from National Grid, a Mass Save sponsor, so a high-efficiency replacement or a switch to a heat pump can generally be checked against Mass Save offers before you buy.
Source: Mass.gov
Right now
Try these before calling; they're safe and sometimes fix the problem outright.
If storm water reached the condenser or an indoor unit, leave the system off at the breaker and have it inspected before running it. Stay clear of wet equipment that's still energized.
A clogged filter can freeze the indoor coil. Swap it, then run only the fan for an hour if you see ice.
Set the thermostat to cool a few degrees below room temperature and check both the indoor and outdoor breakers or disconnects.
Trim plants and remove debris within a couple of feet so air can move freely. Don't open the unit or handle refrigerant lines.
What to expect
The technician checks the electrical components, measures refrigerant pressures and temperatures, inspects the coils, and clears the condensate drain. Near the shore, ask them to look closely at fin condition and electrical connections in the outdoor unit, where salt does the most damage.
Replacing a system brings a permit through Cohasset's Building and Inspections department, which handles electrical inspections; its February 2026 archived page said permits are filed online. If the outdoor unit is moving to a new spot or a raised stand, settle that before the permit is filed.
In older homes that added central air after the fact, the air handler often sits in an attic. Expect the technician to need clear attic access and to check that the drain pan and safety switch are working.
Hire smart
Massachusetts has no single HVAC license. Gas work needs a gas fitter license, oil burner work a Department of Fire Services certificate, ductwork a sheet metal license, and larger refrigeration systems a refrigeration technician license. Most heating and cooling installs need a town permit.
Federal rules require EPA certification to handle refrigerant. Larger systems may need a Massachusetts refrigeration license, and new ductwork a sheet metal license, both searchable on the state's occupational license lookup.
Some manufacturers offer coated coils or corrosion-resistant cabinets for shoreline installs. Ask whether that makes sense for your distance from the water.
If your air conditioner and furnace or boiler are both aging, ask for a heat pump option that cools and heats, alongside a like-for-like AC replacement.
Make sure the written estimate states the equipment model, pad or bracket height, electrical work, permit, and removal of the old unit.
Costs
Repairs depend on what failed. A capacitor, contactor, or drain cleaning is a smaller job than a refrigerant leak search or a compressor replacement, and corrosion-damaged coils often push an older system toward replacement.
For new systems, the size of the house, whether ducts already exist, attic access, electrical upgrades, and raised mounting near the water all affect the total. Ask for written estimates from more than one Cohasset contractor and check which Mass Save offers apply to the equipment quoted.
More help in Cohasset
Every page below is written for Cohasset homes. Or start from the Cohasset hvac guide.
Learning Center
Questions
Still not sure? Send a short request and a local pro can answer the specifics.
Coastal homes generally benefit from more frequent coil cleaning than inland ones, and many owners have it done at each spring tune-up. Use gentle water pressure only, and check whether any outdoor water restrictions are in effect before you start.
Not until a technician inspects it. Saltwater can damage electrical parts and controls in ways that aren't visible, and running the unit could make it worse. Keep it off at the breaker in the meantime.
Expect an electrical permit at minimum. Cohasset's Building and Inspections department handles electrical and building inspections, and permits are filed online, usually by the contractor.
It's worth asking. The town has studied flooding around Cohasset Cove and the harbor since at least 2022, and an outdoor unit is one of the easier pieces of equipment to lift above expected water levels during a replacement.
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