June 4th, 2014

Air Conditioning Seasonal Startup

Home Owners Network

The long cold winter is finally over and people are cranking up their air conditioners for the first time this season.  We are receiving many questions at Home Owners Network about problems people are experiencing.  Here are some tips about how to start your air conditioner for the first time in the spring/summer.AC Unit


  • Wait until the temperature is at least 70° F. outside to start your air conditioner.  Starting your air conditioner at a much lower temperature can damage it.
  • Remove any cover on the outside unit. Covering the outside unit during the winter usually isn’t necessary, but if you cover it, remove the cover.
  • Check the outside unit for physical damage and for clearances to obstructions.  There should be at least 1 foot clearance around the outside unit and at least 3 feet above the unit. This includes clearance to plants. Remove any leaves, mulch, soil, or other materials that are touching the unit.
  • Check the inside unit for obvious damage, loose parts, and loose wires.
  • Check the condensate drain. This is usually a white pipe that runs from the inside unit to the exterior. Make sure the pipe slopes from the inside unit to the exterior or to a floor drain in the basement. Make sure the termination point is clear and that the water has a place to drain. Some installations use a condensate pump; this is harder to check. Check this again after the air conditioner has been running for about 20 minutes to make sure water is coming from the termination point.
  • Check the electrical panel. The circuit breaker or fuse for the inside and outside units should be on.
  • Check the thermostat. If you have a programmable thermostat, make sure the cooling program is set to the times and temperatures you expect. A power failure during the winter could have caused the thermostat to forget its programming.
  • Replace the battery in the programmable thermostat, if there is one. Most programmable thermostats have a backup battery so the thermostat won’t forget the program during a power failure.
  • Replace or clean the filters. You should do this every month regardless of what it says on the package of the more expensive filters. In fact, consider not using the expensive filters because they can restrict air flow when they get dirty.
  • Set the thermostat mode to cooling and the temperature to a few degrees below the inside temperature. The system should start running immediately or at least in a few minutes.
  • Listen to the inside and outside units a few minutes after they start. Turn the thermostat to off if you hear any unusual sounds.
  • Feel the air coming from the supply registers after about 20 minutes. The air should feel cool. Turn the thermostat to off if the air isn’t cool.
  • Check the inside and outside units after 20 minutes. Turn the thermostat to off if you see ice on the coolant tubes or hear any unusual sounds.

The Bottom Line


A qualified technician should conduct routine service of a furnace/air conditioning system at least once a year.  Older systems may benefit from twice-yearly service.  The technician should check all the above items and more during the service call, so it’s a good idea to have this service before you turn on the air conditioning for the season.


We’re here to help at Home Owners Network.  Use our ‘Ask the Experts’ App if you need help.  Please include as many details as possible about your situation so we can provide you with our best advice.


If you need a qualified technician to help you, try our ‘Find a Contractor’ referral service.  Log on to your Home Owners Network account to access the ‘Find a Contractor’ page.

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