Heat Pump Repair in Charleston, SC

Heat pump repair in Charleston usually comes down to one of three things: a defrost problem, an airflow or refrigerant problem, or backup heat that is doing work the heat pump should be doing. Aero Air Techs tests the outdoor unit, the air handler and the controls, shows you what failed and quotes before any repair begins.

This is the system most local homes depend on. EIA's 2023 state data shows about 71% of South Carolina households heat with electricity, and a heat pump does two jobs here. It cools all summer, heats through a short winter and rarely gets a true season off. Parts wear on that schedule.

Heat pump repair in Charleston: broken, or just defrosting?

Check this before you call, because a healthy heat pump does some strange things in cold weather. In heating mode, the outdoor coil runs cold and pulls moisture from the air, so frost builds on it. Our damp winter mornings make that frost common.

To clear it, the system briefly reverses, the outdoor fan stops and the coil warms up. Here is what is normal and what is not.

What you see or hear	Normal?
Steam rising from the outdoor unit for a few minutes	Yes
A whoosh, then the fan stopping for a short time	Yes
Light frost that clears in a cycle	Yes
Lukewarm air that is not hot like a furnace	Yes
Ice that stays more than an hour	No
Ice on the top of the unit or a solid block on the coil	No
Aux heat on all day in mild weather	No
Cold air that keeps coming from the vents	No

Heat pump not heating? What each symptom points to

Each symptom leaves a short list of likely parts, and a safe step for you while you wait.

Symptom	Where we look first	Your move for now
Heat pump frozen solid	Failed defrost board or sensor, low refrigerant, dead fan motor or roof water dripping on the unit	Turn it off or use emergency heat
Outdoor fan not spinning	Capacitor, contactor or fan motor	Shut it off to protect the compressor
Cold air, outdoor unit running	Stuck reversing valve or thermostat wiring	Check that the thermostat is on heat
Weak heat in a freeze	Failed heat strips or a tripped breaker	Check the air handler breaker
Power bill jumped	Heat strips carrying the load	Check for ice and a dirty filter
Short, frequent cycles	Dirty filter, low charge or oversizing	Change the filter

Our post on why heat pumps freeze up goes deeper on ice.

Frozen coils and defrost board repair

Find the reason it froze, because melting the ice fixes nothing. Do not chip at it. Turn the system off or use emergency heat and let it thaw.

Defrost is a small control system. A sensor on the outdoor coil reports temperature, and the board decides when to start and stop the cycle. When either fails, frost keeps building until the coil is blocked. We test the sensor and the board before we replace either one.

We also look past the controls. Low refrigerant, a dead outdoor fan motor and a matted coil can all freeze a unit with a healthy board. So can something simple. A leaking gutter dripping on the cabinet in a freeze will build ice that no defrost cycle can clear.

The reversing valve belongs on this list too. It changes the direction of refrigerant between heating and cooling, and when it sticks, the system may run in only one mode. That repair means opening the refrigerant circuit, so weigh it against the age of the system.

Auxiliary heat strips: when backup is the problem

Heat strips are electric coils in your air handler. They run during defrost, when you raise the thermostat several degrees at once and when a freeze outruns the heat pump. Some use is normal. Long stretches in mild weather are not.

Two different faults live here. Strips that have failed leave you short on heat when it gets cold, and sequencers, limit switches or elements are the usual culprits. Strips that run too often mean the heat pump itself is falling short, so the repair is out at the outdoor unit, or in thermostat settings. Some thermostats need setup for a heat pump. If yours is the issue, see thermostat installation.

How a heat pump service call runs

Each visit follows a set path, and you hear about it as we go.

1. Start with what you saw. Ice, sounds, aux light and when it began all help.
2. Check airflow. Filter, return, blower and coil come first, since low airflow mimics other faults.
3. Test the outdoor unit. Capacitor, contactor, fan motor and defrost controls get measured.
4. Check refrigerant pressures. If the charge is low, there is a leak to find.
5. Test heating mode and backup. We confirm the reversing valve shifts and the strips draw power.
6. Explain and quote. You see what failed and get a line-itemed quote.
7. Repair and verify. With your approval, we repair it and watch it heat.

You leave with the fault named, the failed part shown and a clear read on the condition of the system. That is the deliverable, along with a working repair.

Federal rules apply to the refrigerant side. Venting it is barred under EPA Section 608, and the same rule requires certification for the technician handling it. EPA's Technology Transitions rule leaves existing R-410A equipment alone, so it may stay in service and be repaired. That rule by itself is no reason to replace a working heat pump.

Why salt air hits heat pumps harder

Salt does its work all year, and a heat pump never stops pulling air across its coil. An AC gets a winter break. A heat pump on Folly Beach or Sullivan's Island gets none.

That shows up as white crust on fins, corroded contacts and pinhole leaks in the coil. A corroded coil also holds frost differently and moves less air, so salt can be the root cause of a defrost problem. If you see crust, read about coastal corrosion repair. Regular heat pump maintenance helps here, including a gentle coil rinse and a check of the electrical contacts.

What moves the price of a heat pump repair?

Four things do most of the work.

• The part. A sensor and a reversing valve are very different jobs.
• Refrigerant. Type and amount matter, and so does any leak search.
• Access. Raised platforms, rooftops and tight air handler closets add labor.
• Timing. Night and weekend calls can price differently, so ask first.

Age matters on the big repairs. On a compressor or a leaking coil, ask whether a manufacturer's warranty still applies, then compare the repair against a new heat pump.

Why call Aero Air Techs for heat pump service?

Read what customers wrote, then judge the visit for yourself.

• 4.9★ on Google (16 reviews), per the October 2026 count.
• Both seasons. A reviewer's summary is "cold and heat work amazing."
• Arrival. Another wrote, "They arrived promptly, clearly explained the necessary work."
• Reachable around the clock, going by the hours on our Google listing.

Heat pump repair along the coast and beyond

Based in Charleston, we handle heat pump service across the surrounding areas, including Mount Pleasant, Isle of Palms, Folly Beach and Sullivan's Island. Call with your address and what the unit is doing, and you will get a straight answer on timing. If the heat fails after dark, see our steps for no heat at night.

Heat pumps work year-round, so local wear shows up in both seasons.

• Folly Beach: salt reaches the outdoor coil in every month it runs, not only in summer.
• Isle of Palms: a rental's defrost problem may wait for a guest to report it, so name a contact.
• Sullivan's Island: corroded contacts can stop the reversing valve from getting its signal.
• Mount Pleasant: tell us which floor is affected, since upstairs units run harder.
• Summerville: pine straw blocking the base pan can make a winter freeze-up worse.
• Johns Island: a newer unit may still have parts coverage, so read the plate.
• Hanahan: our shortest trip, handy when a unit iced overnight and still will not clear.
• Awendaw: forest-edge lots shade the unit in winter, which can slow defrost.