An outside unit that hums while the fan stays still is the call we get most in July in Dover, NH, and the cause is usually a failed run capacitor. That inexpensive component starts the compressor and fan, fades for years without complaint, and then quits under peak load. It is far from the only suspect, though. Contactors pit and stop passing clean power, condenser fan bearings dry out, small refrigerant leaks drain away cooling capacity, and evaporator coils ice over when a clogged filter strangles airflow.
At Dover HVAC, each cooling call starts with measurement. Capacitors are metered against the rating on the label. Amp draws on the compressor and fan motor are compared to the data plate. Refrigerant charge is judged by superheat and subcooling, not by pressure readings alone, and any icing prompts a look at the evaporator coil, blower wheel, and filter. This matters because a single warm-air symptom can hide four different faults at four very different prices, and a refrigerant top-off that ignores the leak is just a short-term rental on cold air.
We service central air systems, heat pumps in cooling mode, and ductless mini splits from all major brands, and our trucks stock the summer failure parts: capacitors, contactors, fan motors, hard-start kits, and condensate pumps, so cold air usually returns before we leave the driveway. When a compressor has truly failed on an aging system, we say so plainly and lay out the repair-versus-replace math honestly. For fast AC repair anywhere in Dover, call (351) 345-9323 and we will get the cold air flowing again.
Heating trouble instead? See Furnace Repair in Dover.
How Much Does AC Repair Cost in Dover?
For most Dover homeowners, an AC repair comes in somewhere between $150 and $650. Small electrical parts like capacitors and contactors sit at the low end, while refrigerant leaks, coils, and compressors cost more. Dover HVAC diagnoses the problem first and gives you a written price before any work starts.
| Repair | Typical cost | What it usually means |
|---|---|---|
| Capacitor replacementMost common repair, usually same visit | $150–$400 | The most common AC failure; outdoor unit hums but won't start |
| Contactor replacementWorn relay that stops the condenser from starting | $150–$350 | Burned or pitted switch that powers the outdoor unit |
| Condenser fan motorFan won't spin, unit overheats and shuts down | $300–$700 | Outdoor fan stops, compressor trips on high heat |
| Refrigerant leak repair + rechargeDepends on leak location and refrigerant type | $300–$1,500 | Varies with where the leak is and how much charge is lost |
| Evaporator coil replacementMajor repair; worth weighing against replacement on older systems | $1,000–$2,500 | Major repair; worth weighing against replacement on older systems |
| Compressor replacementOn systems past 10–12 years, replacement usually makes more sense | $1,500–$3,000 | On systems past 10–12 years, replacement usually makes more sense |
Ranges are typical for these repairs; you get an exact quote before any work starts.
What Affects the Price
- The age of the system and whether parts are still readily available
- The type of refrigerant, since older R-22 systems cost far more to recharge
- Whether the repair is urgent, after hours, or can be scheduled
- How hard the equipment is to reach, such as attics, crawlspaces, or rooftops
On older systems we always compare the repair against a replacement, so you can make the call with real numbers. Questions about cost? Call (351) 345-9323.
Warning Signs for AC Repair
Catching these issues early helps you avoid costly problems and protect your property. Here are the most common indicators that it's time to call a professional:
- The system short-cycling every few minutes without cooling the house
- Vents blowing air that is barely cooler than the room
- Higher summer bills even though the house still feels warm and humid
- A hot electrical smell or a tripped breaker whenever the air conditioner kicks on
- Bubbling or hissing noises that point to a possible refrigerant leak
- Water leaking around the indoor unit or from the ceiling below it
- A condenser fan that sits still while the outdoor unit hums
- An iced-over evaporator coil or frozen refrigerant lines
Early Action Saves Money
What seems like a minor issue today can take out a compressor or heat exchanger tomorrow. If you notice any of these signs, contact Dover HVAC at (351) 345-9323 for a prompt inspection.
Your AC Repair Questions Answered
Why Hire a Professional for AC Repair?
Start with the refrigerant. It lives in a sealed, pressurized loop, venting it is prohibited under federal rules, and correct service requires gauges, a vacuum pump, and a recovery machine rather than a store-bought recharge kit. Add capacitors that hold a dangerous charge with the power off and a condensing unit fed by 240 volts, and the risks add up quickly. Then there are the diagnostic traps: an iced coil often points to poor airflow rather than low charge, and topping off a system with an unrepaired leak lets moisture and acid slowly damage the compressor while your money leaks out with the refrigerant.
A professional repair looks at the whole system, not just the symptom. Our technicians meter electrical parts before replacing them, make charge decisions from measured superheat and subcooling, locate leaks with electronic detectors and dye, and check the filter, blower, and static pressure any time airflow could be the issue. The result is a repair that lasts the season instead of a guess that fails in three weeks. If your system is not worth saving, we will tell you directly, backed by numbers rather than a sales pitch.
Our AC Repair Process
Every visit follows a step-by-step method refined over years of hands-on experience. Here's exactly how the AC repair process unfolds:
System Diagnosis
We test capacitors, contactor, motors, and amp draws, evaluate the refrigerant charge by superheat and subcooling, and inspect the coil, filter, and condensate drain to find the true fault.
Honest Findings & Quote
You receive a plain explanation of the fault and its cause, plus a firm price, before we start. When a failed compressor or coil makes replacement the smarter move, we show you the numbers.
Repair From a Stocked Truck
Since the common summer failures, like capacitors, contactors, and fan motors, are stocked on the truck, most AC repairs are wrapped up during the first visit.
Test Under Load
We confirm a healthy temperature split across the coil, verify amp draws and charge, clear the condensate line, and watch a full cooling cycle before we leave.
Questions About AC Repair?
We provide honest advice and upfront pricing on all AC repair work.
Get Help: (351) 345-9323Maintenance Tips for AC Repair
Smart maintenance is almost always cheaper and easier than an early replacement. Follow these tips from our experienced technicians:
- A new buzz or click at startup often means a weak capacitor, so call before it fails
- Book a professional tune-up each spring before the first heat wave finds the weak parts
- Leave vents open in every room, since closing them strains the blower
- Never enclose the condenser; it needs open space on every side to shed heat
- Swap filters monthly while the AC is running hard to keep the evaporator coil from icing
- Flush the condensate drain line with the season's first use to head off clogs
- Keep shrubs two feet from the outdoor unit and gently rinse its coil each spring
Should You DIY or Call a Pro?
A homeowner can swap a filter with ease, but diagnosing capacitors, refrigerant charge, control boards, and error codes calls for the equipment and know-how only a pro brings. Here's a comparison:
| Factor | DIY Attempt | Professional Service |
|---|---|---|
| Refrigerant | Adding refrigerant while it keeps leaking | Leak found and fixed, then charge weighed in |
| Shock Risk | Risk of shock from 240V and stored charge | Power verified off, capacitors discharged |
| Frozen Coils | Defrost it and hope for the best | Cause of the icing traced and corrected |
| Troubleshooting | Guessing between look-alike faults | Instrument readings, not hunches |
| Parts | Whatever capacitor or motor fits | Correct ratings for your exact unit |
| Result | Short-lived relief | Fix proven under full cooling load |
Talk to a AC Repair Expert
Don't let a failing system get worse. Call Dover HVAC now for prompt, professional service.
Call (351) 345-9323 TodayAreas We Serve for AC Repair
Our technicians handle AC repair throughout Dover and the surrounding communities, with the same upfront pricing everywhere we work.