What do common AC problems usually mean?
Most air conditioner failures show up in a handful of ways. The table matches each symptom to its usual causes and what we check; one symptom can have more than one cause, so treat it as a guide, not a diagnosis. For the checks you can make before calling, see AC running but not cooling and AC not turning on.
| What you notice | Likely causes | What we do |
|---|---|---|
| Outdoor unit hums, fan doesn't spin | Weak or failed run capacitor, seized condenser fan motor | Test the capacitor against its rating and check the motor |
| Nothing starts outside when the thermostat calls | Tripped breaker, pulled disconnect, failed contactor, tripped float switch, thermostat or wiring fault | Trace the 24-volt control circuit and the line voltage to where they stop |
| Air from the vents is barely cool | Dirty filter or condenser coil, low refrigerant from a leak, weak compressor | Check airflow and both coils, then superheat and subcooling |
| Ice on the indoor coil or the big copper line | Weak airflow across the indoor coil, low refrigerant | Thaw it, check the filter, blower and returns, then the charge |
| Breaker trips when the compressor starts | Failing capacitor, shorted fan motor, compressor struggling to start, wiring fault | Measure amp draw and windings before anyone resets it again |
| Water around the furnace | Plugged condensate trap or drain line, failed condensate pump | Clear the trap and line, test the pump and float switch |
| Steady hissing or bubbling outside | Refrigerant leak | Leak search, then one price for the repair and recharge |
| Musty, dirty-socks smell at startup | Mold and bacteria on a wet indoor coil or drain pan | Clean the coil, pan and drain |
How does an AC repair visit work?
- You call or book. Call 612-429-3465 any day, 7am to 9pm, or use the form. Tell us what you're seeing: ice, water, a humming outdoor unit, a tripped breaker.
- Simple checks first. Thermostat set to Cool and actually calling, the furnace power switch, the filter, the breaker and the disconnect beside the outdoor unit. Sometimes that's the whole problem.
- The outdoor unit. With the panel off, we test the run capacitor against the rating printed on its side, look for pitted or burned contacts on the contactor, and watch the fan and compressor start. A clamp meter shows whether the compressor is drawing normal current or straining.
- Refrigerant and the indoor side. Gauges and temperature probes go on the lines. Superheat and subcooling tell us whether the charge is right and whether the metering device is doing its job. Then the evaporator coil, blower, drain pan, trap and condensate pump.
- A written price. You get one flat-rate price for the fix. Nothing gets replaced until you approve it, and approving it waives the $79 trip charge.
- Repair and test. If the part is on hand, the repair usually happens on the same visit; if it has to be ordered, we tell you when it will be in. We run the system and check the readings before we leave.
Which AC parts fail most?
Run capacitors
The capacitor gives the compressor and fan motor the kick they need to start and keep running. Heat wears them down, and a weak one is a common reason an outdoor unit hums while the fan sits still. Caught early, it's a quick repair; a compressor that keeps trying to start on a dead capacitor can overheat. Our capacitor cost guide covers what's involved.
Contactors and fan motors
The contactor is the switch the thermostat closes to run the outdoor unit. Ants and pitting can keep it from closing, so nothing runs outside, or weld it shut, so the outdoor unit keeps running with the thermostat off. When the condenser fan motor stops, the compressor overheats, shuts off on its internal overload, cools down, restarts and trips again. Inside you feel warm air; outside you hear the unit start and stop.
Compressors and coils
A compressor that won't start sometimes only needs a new capacitor, and a hard-start kit can buy time on an older unit. One that has locked up or shorted can't be repaired in place, so it gets replaced, and that's the point where we price a new system next to the repair. Evaporator coil leaks tend to be slow: the system loses a little cooling each summer until it freezes up or can't keep up. See signs of a leaking evaporator coil.
We repair every major brand, from Carrier and Trane to Goodman, Lennox and Rheem.
Refrigerant leaks and recharges
Low refrigerant always means a leak. An AC is a sealed system; it doesn't use refrigerant up the way a car burns gas. We check the charge with pressure and temperature readings, search the usual leak spots (the evaporator coil, flare and brazed joints, service valves and Schrader cores) and price the leak repair and recharge together. Topping off without fixing the leak only buys time. What a recharge costs has the national numbers.
The refrigerant type changes the math. R-410A systems can still be repaired and recharged, and a working R-410A system doesn't have to be replaced just because new equipment uses R-454B or R-32. R-22 production and import ended January 1, 2020, so an R-22 system can only be refilled from reclaimed or stockpiled supply, and that gets expensive. Our technicians hold EPA Section 608 certification, which federal law requires to handle refrigerant.
Water around the furnace
In most Minnesota houses the evaporator coil sits on top of the furnace in the basement. On a humid July day it pulls a lot of water out of the air, and that water leaves through a trap and a drain line, often into a small condensate pump that lifts it to a floor drain or laundry tub.
When the trap fills with slime or the pump's float sticks, water backs up into the pan and spills over. Many systems have a float switch that shuts the AC off first, which looks like the AC simply quit. We clear the trap and line, test the pump and the switch, and replace the pump if its motor or check valve is worn. A 90%+ furnace drains into the same pump all winter, so a failing pump can show up in January too. Clearing a clogged condensate drain covers what you can check yourself.
Why do Minnesota air conditioners fail when they do?
Many breakdowns land in the first hot, sticky week of the year, when a system that sat since September suddenly runs for hours. A capacitor that was weak last August doesn't make it, and a contactor that ants moved into over the winter won't pull in. Don't test the AC on a cool spring morning, either. Compressors don't like starting when it's chilly outside, so wait for a warm afternoon.
June brings cottonwood. The fluff mats on the condenser fins, pressures climb, and the compressor works harder for less cooling. With the power off at the disconnect, rinse the fins from the inside out with a garden hose; a pressure washer flattens them. Winter does its damage from above, when snow and ice sliding off the roof bend the fan guard and fins of a condenser parked under the eave.
In older Minneapolis and Saint Paul houses, central air was usually added later: a coil stacked on the furnace in a low basement, and a condenser squeezed between houses or beside the alley garage, where it breathes its own hot air. Radiator houses heated by boilers are often cooled by ductless heads instead, and those fail differently, with clogged drain lines and dirty indoor coils. The town pages cover local detail, including AC repair in Minneapolis, AC repair in Saint Paul and AC repair in Eagan.
One more check on a hot afternoon: if you're enrolled in Xcel Energy's Saver's Switch or AC Rewards, the utility can cycle your AC or adjust your smart thermostat during peak events, and that can look like a breakdown. Some co-ops run similar programs.
How much does AC repair cost?
A service call is a $79 trip charge, waived when you approve the repair. After that you get one written, flat-rate price for the fix, and it doesn't change halfway through. Completed repairs carry a written 1-year parts-and-labor warranty. The price is the same in Minneapolis, Monticello, Northfield or River Falls, with nothing added for distance. Our pricing page lists every published price, and the Minneapolis HVAC cost guide puts them in local context.
Your repair price is set once we find the problem. For context, national cost guides such as HomeGuide (2026 edition) put common AC repairs in the typical national ranges below. They are not our prices.
| Repair | Typical national range, per HomeGuide |
|---|---|
| Capacitor replacement | $150–$400 |
| Contactor replacement | $200–$450 |
| Condenser fan motor | $200–$700 |
| Condensate drain line clearing | $75–$250 |
| Condensate pump replacement | $100–$450 |
| Leak search, repair and recharge | $200–$1,500 |
| R-410A recharge | $100–$320 |
| R-22 recharge | $180–$600 |
| Compressor, out of warranty | $1,800–$2,800 |
| Evaporator coil, out of warranty | $2,500–$4,500 |
If the compressor or coil is still under the manufacturer's parts warranty, HomeGuide's typical national ranges drop to $600–$1,200 for a compressor (labor and refrigerant only) and $1,000–$2,500 for a coil.
Should you repair or replace the AC?
If a repair doesn't make sense on an old system, we'll say so and quote a replacement to compare. The usual tipping points are a leak on an R-22 system, a failed compressor or coil out of warranty on an older unit, and a system that has needed refrigerant more than once. Our cooling page lays out how we weigh it, and AC installation explains what goes into a replacement price. A spring tune-up, $129 or $219 with the furnace, catches weak capacitors and dirty coils before the first heat wave does.
Call 612-429-3465 any day between 7am and 9pm, or use the form on this page.
What's included with ac repair?
- $79 trip charge, waived with an approved repair
- Thermostat, breaker, disconnect and filter checks
- Electrical checks: capacitor, contactor, fan motor and compressor amp draw
- Refrigerant pressure and temperature readings by an EPA 608 certified technician
- Condensate trap, drain line, pump and float switch check
- Written flat-rate repair price before any work
- Written 1-year parts-and-labor warranty on the completed repair
AC Repair questions
Why is my AC running but not cooling?
The usual causes are a condenser coil packed with dirt or cottonwood, a failed run capacitor that leaves the outdoor fan or compressor dead, and low refrigerant from a leak. A plugged filter or a frozen indoor coil can do it too. If you see ice, switch the cooling off and run the fan. Then call 612-429-3465. The $79 trip charge is waived when you approve the repair.
Why is my AC frozen, and what should I do?
Ice forms when the indoor coil gets too cold, usually from too little airflow (a plugged filter, blocked returns, a slow blower) or from low refrigerant. Switch the cooling off and run the fan alone to melt it, and put towels around the furnace, because the drain pan can overflow as it thaws. If it freezes again with a clean filter, call us. Running it iced up is hard on the compressor.
Why is my outdoor unit humming while the fan sits still?
Usually a failed run capacitor or a seized condenser fan motor. The compressor may be trying to start without help, which overheats it, so turn the cooling off at the thermostat and leave it off until it's checked. A steady low hum with the fan turning and cool air inside is normal. A loud hum followed by a tripped breaker can mean a locked compressor.
What does a burning or dirty-socks smell from the AC mean?
A burning or electrical smell means turn the system off at the thermostat and call; it can come from an overheating motor, a failing capacitor or scorched wiring. A musty, dirty-socks smell at the start of a cycle usually comes from mold and bacteria on a wet indoor coil or in a drain pan that holds water. Cleaning the coil, pan and drain fixes it, and a drain that flows keeps it from coming back.
Can you just recharge my AC with refrigerant?
We can, but adding refrigerant without finding the leak means paying for it again. An air conditioner doesn't use refrigerant up. We check the charge with pressure and temperature readings, look for the leak, and price the repair and recharge together. R-410A systems can still be repaired and recharged. R-22 can only come from reclaimed or stockpiled supply, which is expensive, so a leak there often points to replacement.
Should I keep resetting the breaker when my AC trips it?
No. Reset it once. If it trips again, leave it off and call. Repeated trips usually mean a compressor struggling to start, a failing capacitor, a shorted fan motor or a wiring fault, and forcing it can finish off a compressor that might have been saved. Tell us whether it trips right at startup or after a few minutes; that detail helps narrow it down.
Is it normal for my AC to run all afternoon on a hot day?
Yes, within limits. On the hottest, most humid days a correctly sized system can run for hours and still trail the setpoint by a couple of degrees. If it can't get close on an ordinary summer day, look for a dirty filter, a condenser coil packed with cottonwood, low refrigerant or a weak compressor. Change the filter and rinse the outdoor coil with the power off. If that doesn't do it, book a service call.
Is my R-22 air conditioner worth repairing?
Sometimes. If the problem is a capacitor, contactor or fan motor, fix it; those parts have nothing to do with the refrigerant. If it's a leak, a compressor or a coil, the reclaimed R-22 plus labor often costs more than the system is worth. R-22 production and import ended January 1, 2020. We'll give you the repair price and a replacement quote so you can decide with both in hand.
Sources
- HomeGuide cost guides (2026 editions) homeguide.com
- U.S. Environmental Protection Agency epa.gov