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Comfortmaker Central Air Conditioner Not Working
Common reasons for your Comfortmaker central AC not working
The most common reasons for your Comfortmaker central air conditioner not working are electrical power issues, a clogged condensate drain or a bad capacitor.
30% of the time it's the Lack of Power
27% of the time it's the Clogged Drain
25% of the time it's the Bad Capacitor
18% of the time it's the Other Issues
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Comfortmaker Central Air Conditioner Not Working? Here’s What to Check First
When your Comfortmaker central AC won’t work, three common issues could be stopping it from cooling. Before calling for service, check these key issues.
Lack of Electrical Power
When your Comfortmaker central AC won’t power up, check these issues.
Tripped Circuit Breaker
A tripped circuit breaker will cut all power to the central AC unit. Take these steps to check and reset the circuit breaker.
- Check your home’s electrical panel.
- Find the breaker labeled “Air Conditioner” or “HVAC.”
- If it’s in the middle or Off position, reset it by turning it fully Off and then back On.
If the breaker trips again soon after, there could be an electrical problem in the air conditioner unit that needs professional repair.
Thermostat Issues
Problems with the thermostat can prevent the AC unit from getting power or cooling. If the thermostat has no power and you’ve already reset the circuit breaker or replaced the thermostat battery (if it uses a battery), you’ll likely need to schedule HVAC repair service to fix the control failure.
If the thermostat has power, check its settings. Make sure the thermostat is set to the COOL mode and the temperature setting is low enough to call for cooling. Adjust the thermostat setting if necessary.
Clogged Condensate Drain & Tripped Float Switch
Most Comfortmaker central AC systems have a safety float switch that shuts off cooling when the condensate drain line backs up. This prevents water damage but also stops the AC from running or cooling.
Signs of a clogged drain
- AC won’t run at all
- Water dripping from under the air handler
- Unit blowing warm air with no error codes
Basic troubleshooting
When you see water dripping below the inside unit and no water coming through the AC condensate drain hose outside you house, the drain line is likely clogged.
If you have a wet/dry shop vacuum, you can try vacuuming the drain line outside at the termination point. You may need to use a plumber’s snake to clear the drain line if it’s severely clogged.
View this troubleshooting video for more tips on clearing a clogged AC drain line and keeping it clear:
If the drain pan below the evaporator keeps filling and won’t drain, professional HVAC repair service is needed.
Bad Capacitor
Your Comfortmaker AC has capacitors that help the compressor and condenser fan motor start. When a capacitor fails, the outdoor unit may hum but not start, or it may start and shut off quickly.
How to Spot the Signs of a Bad Capacitor
- Outdoor fan isn’t spinning
- AC turns on but blows warm air
- A faint humming sound comes from the outdoor unit
Safe troubleshooting you can do
Capacitors store electricity even when the power is off. Do not open the outdoor unit or touch the capacitor.
However, you can do one safe check:
- Turn off power to the outdoor unit at the disconnect box or house circuit breaker.
- Look through the grille to see if the fan blades are obstructed or if debris is preventing the fan from turning. Clear any debris that you find if safely possible.
- Restore power and restart the central AC system.
If the fan still won’t run or the unit only hums, an HVAC technician likely needs to replace the capacitor.
Schedule Trusted Comfortmaker Central Air Conditioning Repair
Sears Home Services repairs all Comfortmaker central AC models.
Our nationwide service network provides Comfortmaker air conditioner repair in every major metro area across the country including:
- Los Angeles
- San Diego
- Miami
- Dallas
- Houston
- Atlanta and more
Our licensed technicians can quickly diagnose the problem—whether it’s a bad capacitor, faulty control board, defective thermostat or low refrigerant issue—and get your Comfortmaker system cooling again fast.
- Expert air conditioner repair technicians
- Same-day and next-day appointments available
- All repairs backed by the Sears satisfaction guarantee
Call 1-800-469-4663 or schedule your AC repair online today to get your cooling restored quickly.
Comfortmaker Central Air repair is quick and easy
EASY SCHEDULING
Book online in less than a minute.
DIAGNOSTIC FEE
Apply your diagnostic fee to the costs of repair.
PROTECTION PLANS
Save up to $150 on your repair if you enroll in a home warranty.
Frequently Asked Questions
Why is my Comfortmaker central air conditioner not turning on at all?
When your Comfortmaker central AC won’t start, the most common causes are a tripped circuit breaker, thermostat power/settings problems, or a clogged condensate drain that triggered the float switch. Start by checking your breaker and thermostat settings. If the system still won’t run, a technician may need to diagnose an electrical or control issue.
What are the signs of a bad AC capacitor?
A bad capacitor often shows up as an outdoor unit that hums but doesn’t start, a fan that won’t spin, or an AC that runs briefly and shuts off. You may also notice warm air blowing indoors even though the system is on. Capacitor replacement should be handled by a licensed HVAC technician.
Can I safely troubleshoot an outdoor AC unit if it’s humming?
Yes—only in a limited way. Turn off power at the disconnect box or breaker, then look through the grille to check whether debris is blocking the fan blades. Clear any visible obstruction if you can do so safely. Do not open the outdoor cabinet or touch electrical components, since capacitors can store a dangerous charge.
How do I know if my AC condensate drain line is clogged?
Common signs include the AC shutting off unexpectedly, water dripping under the indoor air handler, or warm air blowing. If you see water around the unit and no drainage outside, the line may be clogged. You can try vacuuming the drain line at the outside termination point with a wet/dry shop vac, but if the pan keeps filling, professional repair is recommended.
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Glossary Terms
The 608 Certification, mandated by the Environmental Protection Agency (EPA), is required for HVAC technicians to legally handle refrigerants. It ensures technicians understand refrigerant types, environmental impact, and proper handling techniques.
A compressor is a mechanical device that increases the pressure of a gas by reducing its volume, essential in various systems including refrigerators, air conditioners, and HVAC units for cooling and refrigeration processes.
A condenser is a component of HVAC and refrigeration systems, responsible for releasing absorbed heat from the refrigerant into the outside air or a water line, thus facilitating the cooling process.
A capacitor in an AC unit is an electrical component that stores and releases electrical energy to help start the motor and stabilize the voltage during operation.