Clogged HVAC drain lines

There are several steps you can take to ensure that clogged HVAC drain lines don’t happen to you. To ensure your HVAC drain line stays clear between preventative maintenances, we’re going to look at what you can do as a homeowner to prevent these clogged HVAC drain lines.

At the air handler:

  • Condensation will collect in the pan under the air handler
  • It will flow down the condensate line and outside by the outdoor unit
  • Initially the inside of the PVC pipe has a sleek oil based coating – however over time water sets in there, algae builds up and you have your initial clog
  • Some will recommend pouring bleach in the line. Bleach will corrode any copper lines through your system. For that reason, we recommend white vinegar.
  • Some also recommend using a shop vac or high pressure air to blow out the line. We use a garden hose and flush with fresh water.
  • Routinely pouring 1/2 cup of vinegar followed by warm water should keep the algae at bay.
  • It is also good to have float switches installed. They will shut the system off when the pan fills with water so it does not overflow. If your unit is in the attic, we don’t need to tell you what will happen if the pan overflows to the attic floor.
  • If water has collected in the drain pan, be sure to vacuum it out with a wet-vac. You can even clean with a little soapy water to prevent mildew.


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North Myrtle Beach HVAC & Refrigeration

LHT Cooling, Heating & Refrigeration is a North Myrtle Beach HVAC and commercial refrigeration company serving the South Carolina Grand Strand, Carolina Shores and North Carolina. LHT services and repairs heat pumps, heating units, air conditioning units, furnaces, ventilation systems, indoor air quality, humidifications, ductless systems, boilers, reach-in coolers, walk-in coolers, reach-in freezers, walk-in freezers, ice machines, blast chillers and refrigerated displays.

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