AC Blowing Warm Air After Power Outage. What to Check?

Power outages can cause plenty of damage to your electric appliances. Air conditioners are no exception.

If your AC started blowing warm air after a power outage, you should first check for a tripped circuit breaker (some units have two breakers and one of them is responsible for the cooling). You might also have to assess the capacitor’s condition and test the compressor.

AC Blowing Warm Air After Power Outage. What to Check?

Check the breaker

You might be thinking that if your air conditioner had tripped the breaker then the whole system wouldn’t be working. But that is not always the case.

Some cooling systems have two breakers – one for the outdoor unit and one for the indoor unit. If the breaker only to the outdoor unit had tripped, then the system would be circulating air, but it will fail to cool it.

Assess the capacitor’s condition

A voltage surge can blow the capacitor. In such a case, the indoor unit will continue to operate, but you won’t be receiving any cooled air.

You can visually assess the capacitor. Take a look at the outdoor unit – if the top is leaking an oily substance, then the capacitor has most likely failed.

Read: Why HVAC Damper Keeps Getting Stuck Closed?

Test your AC compressor

A power surge can also cause damage to the compressor. If that happens, then the unit won’t be able to circulate the refrigerant.

Testing the compressor involves a multimeter, so you might want to leave that to a professional. 

Why Is My AC Not Cooling After Power Outage?

The chances are high that your air conditioner will not be able to cool after a power outage for around 30 minutes. If you turn it on sooner than half an hour has passed, you might have to wait for the unit to restore its internal circuity.

Your unit will most likely return to normal operation if you give it that extra time

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AC Not Blowing Air After Power Outage

If your air conditioner is not blowing any air after a power outage, then you should first make sure that the unit is actually on. Locate the AC breaker and reset the system.

You might also want to check the household fuse. If it has blown, then the air conditioner’s blower will not be operating.

Unfortunately, the actual blower might get damaged during a voltage surge. This might happen if you left the air conditioner on during the power outage. 

Read: How To Tell If HVAC Zone Damper Is Normally Closed Or Normally Open? 

Fujitsu Mini Split Not Working After Power Outage

Check for a tripped circuit breaker and a blown fuse.

Bear in mind that a Fujitsu mini-split will not start working immediately after the power returns. The unit is going to need at least 3 minutes to restart.

Window AC Unit Won’t Turn on After Power Outage

A window air conditioner will not turn on by itself after a power outage if the breaker got tripped. In a lot of cases, you would have to reset the unit by unplugging it and then give the system about half an hour to reset. 

Read: Why HVAC Zone Damper Actuator Making A Clicking Noise? How To Troubleshoot?

How Long Does It Take for AC to Come Back on After Power Outage?

You shouldn’t expect your air conditioner to immediately start cooling as it normally would right after a power outage.

Ideally, you would want to turn the system off during the actual power outage and reset the unit once the power returns

It might take the air conditioner up to an hour to reset its internal circuity. In the majority of cases, it will happen earlier (if the inside components have not been damaged). 

Read: Should An HVAC Zone Damper Bleed Air?

How Do I Reset My AC After a Power Outage?

You can always reset your unit by pushing the reset button. But it is recommended to use the circuit breaker to reboot the system after a power outage.

  1. Turn the thermostat off.
  2. Flip the AC break to ‘off’ and then back to ‘on’.
  3. Wait for 30 minutes.
  4. Turn the thermostat on and make sure that the set temperature is below room temperature and that the device is set to ‘cool’ mode.

Do You Have to Reset AC After Power Outage?

If your air conditioner hasn’t been turned off during the power outage, then it might turn on by itself once the power returns.

However, it is still recommended to reset the unit at the circuit breaker, so that the air conditioner has a chance to reboot its internal circuity without a rush. 

Can a Power Outage Mess Up Your AC?

A power outage can definitely damage your cooling equipment, and this, in its turn, can make the air conditioner start blowing warm air or no air at all.

To avoid that, make sure to switch the AC (and any other appliances) off, as soon as a power outage occurs.

Read: Why HVAC Dual Zone System Acting As A Single Zone?

Can a Power Surge Damage an AC Compressor?

A voltage surge can burn up fuses and wires and lead to damage of the capacitor and the compressor. The replacement of the latter might cost you a small fortune. 

How Do I Know If My AC Fuse Is Blown?

After checking for a tripped breaker, you might want to inspect the unit for any blown fuses. If the fuse is blown, the outdoor unit will stop operating and your AC might end up blowing warm air. 

One of the best ways to check for a blown fuse is by using a voltmeter.

Do I Need to Reset the Breaker for My AC to Work?

If the AC breaker had tripped, then you would, of course, have to flip it back to ‘on’. Otherwise, the air conditioning unit will not work.

You can also try resetting the system at the breaker if your unit is not operating correctly (in some cases, it might help).

Why Did My AC Stop Working After a Storm?

  • Storms are usually accompanied by strong winds. If that was the case, then your AC might stop working because there is debris and twigs stuck in its outdoor unit.
  • Your air conditioner might get struck by lightning, especially, if you live in a high-rise and have a window AC. The unit’s capacitor can easily get damaged by lightning, as well as the compressor.
  • If there was a power outage during the storm, then your air-con can get damaged when the power returns. Voltage surges can affect the capacitor, compressor, or motor and trip the circuit breaker.

Read: How To Adjust HVAC Automatic Dampers?

Are Power Surges Covered by Homeowners Insurance?

Not all policies cover power surges. Whether or not the damage is covered can vary based on what caused the voltage surge (old wiring, lightning strikes, or power company issues).

Do I Need a Surge Protector on My HVAC Unit?

A surge protector is an element that interrupts an energy spike and saves your AC from the excess charge. 

In case of a large power surge, the protector will get destroyed, but it will cost you only a small amount to replace the element. That would certainly be better than having to replace the unit’s compressor, for example.

Do AC Units Have Surge Protectors?

The majority of air conditioners do not come equipped with surge protectors. These elements are sold separately and will usually cost you between $75 and $100.