HVAC Repair

When your heating or cooling system lets you down during extreme weather, you need an HVAC company you can rely on. 

We proudly offer 24/7/365 emergency services for urgent HVAC needs.

A CPS HVAC service technician performs repairs on a Carrier indoor air handler during an HVAC service call.

Heating System Repair

If you notice any of these issues with your heating system, it’s essential to call in the professionals at Comfort Plus Services right away. Ignoring these problems can lead to more severe damage and costly repairs down the line. Our technicians have experience repairing furnaces, heat pumps, boilers, mini-splits, and ducted systems.

Not sure if you need repairs? Check out common heating problems and what causes them.

Even the most well-maintained heating systems can experience issues over time. Some of the most common problems we encounter include:

  • Thermostat malfunctions
  • Dirty or clogged filters and ductwork
  • Pilot light or ignition problems

  • Leaks

Cooling System Repair

When your air conditioner breaks down, you need a reliable and experienced team to get it back up and running quickly. At Comfort Plus Services, we specialize in air conditioning repair services for homeowners and businesses. Our skilled, NATE-certified technicians have the knowledge and expertise to diagnose and repair any issue with your AC system, ensuring you stay cool and comfortable all summer long.

No matter what problem you’re facing with your air conditioner, our team has the skills and experience to get it fixed quickly and efficiently. We pride ourselves on providing quality services, and our knowledgeable and trained technicians always strive to achieve 100% customer satisfaction.

Not sure if you need repairs? Check out some common HVAC symptoms and their potential causes to be sure.

Our team has experience repairing a wide range of air conditioning issues, including:

  • Refrigerant leaks
  • Frozen evaporator coils
  • Clogged condensate drains
  • Malfunctioning compressors
  • Damaged fan motors
  • Electrical issues
  • Coolant flushes

Avoid Costly Repairs with an HVAC Service Plan

Regular HVAC maintenance not only prevents unexpected breakdowns, but also improves energy efficiency, potentially reducing your utility bills by up to 30%. Enroll in a Service Plan with Comfort Plus Services, and you’ll enjoy an annual comprehensive tune-up, 15% off repairs, and priority service.

Our Service Plans offer peace of mind, knowing that your home’s vital systems are in top condition. With options tailored to your specific needs, you can rest assured that your HVAC system will run smoothly throughout the year. Don’t wait for costly repairs – invest in preventative care and experience the benefits of our Service Plans today.

Schedule Your HVAC Repair Appointment

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Common HVAC Symptoms and What Causes Them

When your heating or cooling system isn’t working, you’ll notice symptoms that could be caused by different mechanical issues. Some require immediate service, and some you can remedy on your own. Here are a few of the most common HVAC symptoms we see, what usually causes them, and how you know when it’s time to call in the experts.

Your system is running and the thermostat is set correctly, but the house won’t cool down.

The most common causes are a clogged air filter restricting airflow, low refrigerant from a slow leak, a dirty or frozen evaporator coil, or a failing compressor. On the Eastern Shore, salt air corrosion on the outdoor condenser coil is also a frequent contributor that accelerates coil degradation faster than in inland markets.

Check first: Replace the filter if it’s been more than 60 days. Look for ice on the refrigerant line near the outdoor unit or on the air handler. If you see ice, turn the system fully off and let it thaw before running it again.

Call us if: The filter is clean, there’s no ice, and the system still isn’t cooling after 30 minutes. Also call immediately if you see water pooling near the air handler (the inside unit). That’s likely a frozen coil that has started thawing and needs attention before it causes water damage.

We cover this in detail in our blog: Why Your AC Is Running But Not Cooling Your House.

The system is blowing, but the air is warmer than it should be.

This is often confused with the symptom above, but there’s a distinction. If the system is running and blowing air that feels room temperature or warmer, the most likely causes are a refrigerant leak, a tripped breaker on the outdoor unit (the air handler runs but the compressor doesn’t), a thermostat set to “fan only” instead of “cool,” or frozen coils restricting heat exchange.

Check first: Confirm the thermostat is set to “cool” and the fan is set to “auto,” not “on.” Go outside and verify the outdoor unit is actually running; you should hear the compressor and see the fan spinning. If the outdoor unit is silent while the air handler runs, check the breaker.

Call us if: The outdoor unit is running, the thermostat is set correctly, and air is still warm. A refrigerant leak won’t resolve on its own and the system will continue to lose capacity until it’s repaired.

HVAC systems make noise when they run, but new or changing sounds are almost always worth investigating. Different sounds point to different problems.

Banging or clanking usually means something is loose or broken inside the unit. It could be a fan blade, a loose panel, or in worse cases a broken component inside the compressor. Grinding points to motor bearing failure, which will worsen quickly if the system keeps running. Hissing can mean a refrigerant leak at a fitting or valve, or a ductwork pressure issue. Squealing typically indicates a worn blower belt or motor bearing in older systems.

Check first: A single bang on startup, especially in cold weather, is often just the ductwork expanding. Persistent or rhythmic noise during operation is the signal to act.

Call us if: The noise is new, consistent, or getting louder. Grinding and banging in particular indicate mechanical stress that compounds fast, and running the system through a noise like that risks turning a simple repair into a far more expensive service call.

Short-cycling is when your system starts, runs for a minute or two, shuts off, and then starts again. It never completes a full cooling or heating cycle.

It’s hard on the equipment because the startup phase draws the most power and creates the most mechanical stress. Common causes include an oversized unit that cools the space too quickly and triggers the thermostat before a full cycle completes, a dirty air filter, a failing thermostat or faulty sensor, low refrigerant, or a frozen evaporator coil. In summer, a refrigerant issue and a clogged filter are the most frequent culprits.

Check first: Replace the filter. If short-cycling stops, that was the cause. If it continues, note how long the system runs before shutting off. That timing is useful diagnostic information for the technician.

Call us if: Short-cycling continues after a filter change, or if the system is less than five years old. Short-cycling on a relatively new system often points to an installation or sizing issue that should be addressed under any applicable warranty.

You can feel air, but barely, when you hold your hand up to the vent.

Weak airflow usually means something is blocking or restricting air movement through the system. The most common causes are a clogged air filter, a failing blower motor, blocked or collapsed ductwork, or a frozen evaporator coil. In coastal homes on the Eastern Shore, duct leakage from humidity cycling and temperature fluctuations is a contributing factor we see regularly. In those cases, conditioned air leaks out into unconditioned spaces (like an attic or crawlspace) before it reaches the vents.

Check first: Replace the filter. If airflow improves noticeably, that was the cause. Also check that supply vents throughout the home are open and unobstructed by furniture or rugs.

Call us if: Airflow is weak after a filter change, or if only certain rooms or zones are affected while others are fine. That pattern points to a ductwork issue that needs inspection.

Water near the air handler is the symptom that requires an emergency service call. Even a slow leak can cause significant damage to ceilings, walls, and flooring in a short time, and mold can begin developing within 24 to 48 hours in Delmarva’s humid summers.

The most common causes are a clogged condensate drain line, a cracked or overflowing drain pan, a frozen evaporator coil that has thawed and released more water than the drain pan can handle, or a disconnected drain hose. Condensate drain clogs are by far the most frequent cause, because algae and debris accumulate in the line and block drainage. It’s also one of the most preventable issues with regular maintenance.

Check first: Turn the system off immediately to stop water from accumulating. Begin drying the area. Do not turn the system back on until the source is identified.

Call us: Right away. Water intrusion doesn’t wait, and identifying whether it’s a drain clog, a cracked pan, or a thawing coil determines what comes next. This is one of the most common repair calls we receive in summer, and our technicians carry the tools to clear a drain line and assess for damage on the same visit. A service plan includes annual drain line maintenance that prevents most of these calls from happening in the first place.

Smells coming from your HVAC system are worth taking seriously. Some are minor, and some require you to act immediately.

A musty or moldy smell usually means mold or mildew has developed in the ductwork, on the evaporator coil, or in a wet drain pan. It won’t go away on its own and can affect air quality throughout the home. We cover musty HVAC smells in detail in this blog post.

A burning smell — like burning plastic, rubber, or an electrical smell — means turn the system off immediately and call for service. Electrical faults and overheating motors are fire risks. Don’t run the system again until a technician has inspected it.

A rotten egg or sulfur smell, if your home uses gas, should be treated as a potential gas leak. Leave the home, don’t operate any switches or appliances, and call emergency services and your gas provider before calling us.

Call us: For a musty smell, schedule a diagnostic at your convenience. For a burning smell, call immediately at 866-950-2653 and treat it as an emergency.

A breaker that trips once after a storm or power event is usually not a concern. A breaker that trips repeatedly when you try to run the HVAC system is the equipment telling you something is wrong.

Common causes are an electrical fault in the system, a short in the compressor, a dirty condenser coil causing the system to draw excessive power as it struggles to reject heat, or a wiring issue. In older systems, a compressor that is beginning to fail will often draw higher current before it fails completely, and a tripping breaker is sometimes the first sign.

Do not repeatedly reset the breaker and restart the system. The breaker is protecting both your equipment and your home. Each restart attempt on a faulting system adds stress to the compressor, which is the most expensive component to replace.

Call us: Schedule a diagnostic before resetting the breaker a second time. We’ll identify whether the issue is in the electrical system, the condenser, or the compressor, and give you a clear picture of the cost of repair if the compressor is involved.

Common Heating Problems and What Causes Them

When your heat stops working on a cold night, it helps to know which problems you can fix in a few minutes and which ones need a professional’s touch. Here are the heating problems we see most often across Delmarva, what usually causes them, and when to call us.

Common heating problems: causes, what to check first, and when to call Comfort Plus Services
What you noticeMost common causesTry this firstCall us when
Furnace won't turn on or won't lightThermostat setting or batteries, switch or breaker off, dirty flame sensor, failed igniter, empty oil or propane tankSet thermostat to Heat, check the switch and breaker, check the fuel gaugeIt won't light after one reset, or it lights and shuts off in seconds
Furnace blowing cold airFan set to On, clogged filter, ignition or fuel problem, leaky ductworkSet fan to Auto, replace the filter, wait a few minutes after the burner lightsAir stays cool after the burner runs for several minutes
Heat pump stuck on AUX or EM heatVery cold weather, defrost cycle, large thermostat jump, thermostat setup, low refrigerant, defrost control problemMake sure Emergency Heat is off, raise the setting graduallyAUX runs most of the day above freezing, or your electric bill jumped
Heat pump iced overNormal frost during defrost, failed defrost control, low refrigerant, dirty coil, dripping gutter, wind exposureClear debris and snow, let a defrost cycle finishIce stays for hours, covers the top of the unit, or the fan won't turn
Furnace short cyclingClogged filter, dirty flame sensor, thermostat location, blocked vent pipe, oversized furnaceReplace the filter, check outdoor vent pipesIt continues after a filter change
Burning smell when heat comes onDust burning off on first use, overheating motor, electrical problemReplace the filter, let it run, open a windowSmell lasts past the first day or smells electrical
Boom, grinding, or screechingDelayed ignition, motor bearing failure, loose panel or blower partNote when the sound happensAny boom at ignition, or grinding that keeps going
Carbon monoxide alarmMalfunctioning fuel-burning appliance or blocked ventingGet everyone outside and call 911After responders clear the home, before using the heat again

You set the thermostat and nothing happens, or the blower runs but the burner never lights.

The most common causes are a thermostat set to Cool or running on dead batteries, a furnace power switch that was turned off (it often looks like a light switch near the unit), a tripped breaker, a dirty flame sensor, or a failed igniter.

In homes with oil or propane heat, an empty tank causes the same symptom, and a propane system that ran out needs a safety check before it’s relit.

Check first: Make sure the thermostat is set to Heat and a few degrees above room temperature, and replace its batteries if it uses them. Confirm the furnace switch is on and the breaker hasn’t tripped. Check your oil or propane gauge.

Call us if: The furnace still won’t light after one reset, or it lights and then shuts off within a few seconds. That pattern usually points to a dirty or failing flame sensor, which our technicians can often clean or replace on the same visit. If you smell gas, leave the house and call your gas provider or 911 from outside before you call us.

The blower runs, but the air from the vents feels cool or room temperature.

Check the thermostat fan setting first. When the fan is set to On, it keeps running between heating cycles and moves unheated air through the house.

Other causes include a clogged filter that makes the furnace overheat and shut off its burner as a safety step, an ignition or flame sensor problem, a fuel supply issue, or leaky ductwork in an attic or crawlspace that cools the air before it reaches your rooms.

If you have a heat pump, air that feels lukewarm can be normal. Heat pump air often feels cooler to the touch than furnace air, even when the system is working correctly.

Check first: Set the fan to Auto and replace the filter if it’s been more than 60 days. Give the system a few minutes after the burner lights, since many furnaces wait to start the blower until the heat exchanger warms up.

Call us if: The air stays cool after the burner has been running for several minutes, or the furnace keeps starting and stopping.

Your thermostat shows AUX or EM HEAT, or your winter electric bill was much higher than you expected.

Most heat pumps have electric heat strips as a backup. Auxiliary heat turns on by itself when the heat pump needs help: during a defrost cycle, on the coldest days, or after a large jump in the thermostat setting. Short stretches of auxiliary heat are normal. Emergency heat is a setting you choose, and it runs the electric strips alone with the heat pump turned off.

Electric heat strips cost much more to run than the heat pump, so a system that leans on them every day shows it on the electric bill. The U.S. Department of Energy notes that heat pumps with electric backup heat should have controls that keep the strips from running when they aren’t needed, and that this is one of the most commonly missed steps in heat pump installation.

Backup heat that runs for long stretches in mild weather usually points to a thermostat that wasn’t set up for a heat pump, low refrigerant, a defrost control problem, or an outdoor unit that has stopped running.

Check first: Make sure the thermostat isn’t set to Emergency Heat. Raise the setting a degree or two at a time, and avoid deep setbacks overnight, since a large recovery in the morning brings on the backup heat.

Call us if: AUX shows on the thermostat most of the day when it’s above freezing outside, or the outdoor unit isn’t running while the indoor unit is.

Adding Propane Heat for the Coldest Days

In Delaware, Delmarva Power’s winter supply rate for residential heating customers rose 17% on June 1, 2026. If your heat pump leaned on its electric backup heat last winter and the bill caught you off guard, adding propane heat can take on part of the load during the coldest weeks. In cooperation with PepUp, a Tri Gas Family Company, we can add propane to your home for supplemental winter heat. Learn more about adding propane on our System Conversions page, or contact us at 866-950-2653 to talk through what fits your home.

You see frost or ice on the outdoor unit, or a cloud of steam rising from it.

Light frost on the outdoor coil is normal in cold, damp weather. The heat pump clears it with a defrost cycle, reversing the flow of refrigerant for a few minutes to warm the outdoor coil. During defrost you may hear a whoosh, the outdoor fan may stop, and steam can rise off the unit.

A unit covered in solid ice has a problem. Common causes include a failed defrost sensor or control board, low refrigerant, a dirty coil, an outdoor fan that won’t turn, or water dripping onto the unit from a gutter or roof edge. Homes near the Bay and the ocean see more wind, and the Department of Energy notes that high winds can cause defrosting problems for outdoor units.

Check first: Clear snow, leaves, and debris from around the unit, and make sure nothing is dripping onto it. Give it an hour to run through a defrost cycle. Don’t chip ice off the coil, because that can damage the fins and refrigerant lines.

Call us if: The coil stays iced over for more than a few hours, ice covers the top of the unit, or the outdoor fan won’t turn.

The furnace starts, runs for a minute or two, shuts off, and starts again.

A clogged filter is the most frequent cause. With too little airflow, the furnace overheats and a safety switch shuts off the burner. Other causes include a dirty flame sensor, a thermostat mounted near a heat source or a drafty spot, a blocked exhaust vent or intake pipe, or a furnace that’s too large for the home.

Check first: Replace the filter. If you have a high-efficiency furnace with plastic vent pipes on an outside wall, make sure leaves, snow, or a nest isn’t blocking the pipes.

Call us if: Short cycling continues after a filter change. Repeated starts wear out the igniter and other parts, and a blocked vent can be a safety issue.

You turn on the heat for the first time and smell something burning.

A dusty, burnt, or musty HVAC system smell during the first few heating cycles of the season is common. Dust settles on the heat exchanger or heat strips over the summer and burns off once the system warms up, and the smell should fade within a day.

A smell like hot plastic, rubber, or wiring points to an overheating motor or an electrical problem. That needs attention right away.

Check first: Replace the filter and let the system run. Open a window if the dust smell bothers you.

Call us if: The smell lasts past the first day, smells like electrical burning, or you see smoke. Turn the system off at the thermostat and call 866-950-2653 right away.

You hear a boom, bang, grinding, or screech when the heat runs.

A loud boom when the burner lights usually means delayed ignition. Gas builds up for a moment before it lights, often because the burners are dirty. Grinding or screeching points to a failing blower motor bearing or inducer motor. Rattling can come from a loose panel or a part inside the blower housing.

Some sounds are normal. A heat pump makes a whoosh when it switches into or out of defrost, and ductwork can tick as it warms up and cools down.

Check first: Note when the sound happens and how long it lasts. That information helps a technician find the cause faster.

Call us if: You hear a boom at ignition, or grinding or screeching that keeps going. Delayed ignition can crack a heat exchanger over time, so don’t keep running a furnace that booms when it starts.

Treat every carbon monoxide alarm as an emergency. Get everyone outside to fresh air right away and call 911 from outside. The U.S. Consumer Product Safety Commission lists malfunctioning fuel-burning appliances, such as furnaces, water heaters, and room heaters, among the common sources of carbon monoxide in a home.

After emergency responders clear the house, call us at 866-950-2653 before you run your heating system again. We’ll inspect the furnace or boiler, the water heater, and the venting to find the source. The CPSC recommends a yearly inspection of your heating system by a qualified professional, including the exhaust venting, which makes a fall heating tune-up a good habit.

Frequently Asked Questions: HVAC Repair

Treat it as an emergency if you smell burning from the system, if the breaker keeps tripping, if water is actively leaking near the air handler, or if the system has stopped working entirely during extreme heat or cold. We offer 24/7 emergency HVAC service across the Eastern Shore and Delaware; call 866-950-2653 any time.

Most diagnostic and repair visits take one to three hours. Simple issues are often completed in the same visit. More complex repairs involving the compressor, heat exchanger, or a refrigerant leak with line repair may require a follow-up visit once parts are sourced. We’ll give you a clear estimate before any work begins.

The general benchmark is the 50% rule: if the repair cost exceeds 50% of the cost of a new system and the unit is more than 10 years old, replacement is usually the better investment. Factors like refrigerant type (older R-22 systems are expensive to recharge), repair frequency, and efficiency also weigh in. We’ll walk you through the numbers honestly at your diagnostic visit. Here’s a guide to repair vs. replacement, if you’d like to learn more.

Yes. Our NATE-certified technicians are trained to diagnose and repair all major residential HVAC brands, including Carrier, Trane, Lennox, Goodman, Rheem, and others. Comfort Plus Services is a Carrier Factory Authorized Dealer and a Mitsubishi Electric Diamond Elite Contractor.

Yes, most of the issues that require HVAC repairs are caught during a routine tune-up before they become repair calls. Annual maintenance is the most cost-effective thing you can do for the life of your system. See our HVAC service plans.

Yes. We serve Sussex County, Delaware and the surrounding beach communities, with a local office in Georgetown, DE. We work with vacation homeowners and property managers who need reliable service before and during rental season. Call 866-950-2653 to schedule.

The most common reason is backup electric heat running, for those with electric heat pumps. Thermostat setup, low refrigerant, or a defrost problem can keep auxiliary heat on even in mild weather.

Auxiliary (or backup, or emergency) heat uses electric heat strips, which cost much more to run than the heat pump itself. To get an idea of anticipated Delmarva heating costs for this winter, read the PepUp winter heating costs outlook so you’ll know what to expect.

A technician can check your thermostat settings, refrigerant charge, and defrost controls during a diagnostic visit. If your bills are still higher than you’d like, we can talk through adding propane heat to your home. Call 866-950-2653 to learn more.

Light frost and steam during a defrost cycle are normal. A unit that stays covered in ice for hours could indicate a defrost control, refrigerant, or airflow problem.

Homes near the Bay and the ocean see more wind and moisture, which can make icing more common. Keep the area around the outdoor unit clear, and call us at 866-950-2653 if the ice continues to be an issue.

Get everyone outside to fresh air and call 911. After responders say it’s safe, call us to inspect your heating system and venting before you use it again.

The CPSC recommends a yearly heating system inspection by a qualified professional and testing your CO alarms once a month. Call 866-950-2653 to schedule a heating system inspection and tune-up.

Yes. In collaboration with PepUp, a Tri Gas Family Company, we can add propane to your home as supplemental heat, so your heat pump relies less on electric backup on the coldest days. Here’s a guide from PepUp to help you compare electric to propane for home heating.

PepUp handles the propane tank and fuel deliveries. Visit our System Conversions page to learn more, or call 866-950-2653 to talk through your options.