Air Conditioning Leaks

Thanks to Hamstra Heating & Cooling for the article this month.

What can cause air conditioning water leaks?

Clogged Drain. A clogged drain hole/line causes the drain pan to overflow. During the warmer months of the year when the air conditioning unit is working hard there is a lot of moisture being pulled out of the air into the facility. As this water drips down the evaporator coil and flows into the drain pan, there is algae and other debris that form and run through the drain line. Eventually, if not maintained, this algae and debris will clog the drain line, forcing the water to overflow the pan.

Damaged Pump. Leaking water could be a sign that you have a faulty or damaged pump. If the pump is broken it may not be properly pumping the excess water from the drain pan, causing it to overflow.

Improper Air Flow. It is possible that the air flow over the indoor evaporator coil is restricted due to either a dirty coil or a dirty air filter. In either case this will cause the evaporator coil to ice up and leak water over the edge of the condensate drain pan. Proper maintenance of your heating & cooling system will help prevent water leaks. However, our desert climate, including dust and critters, can cause drain clogs between maintenance visits. A condensate drain safety shut-off device can drastically prevent water damage and is required per code IRC M1411.3.1.

Preventative Actions. Some systems at the time of installation did not include these. Make sure the following are in good working order:

  • 5 amp high-capacity sensor designed for secondary drains. The sensor will shut down the unit if the drain is plugged. The high capacity sensor eliminates false shut offs caused by trapped condensation.
  • As an added precaution, make sure your HVAC system has a 2-in-1 secondary drain + secondary pan sensor. All of our installed sensors include a moisture detector LED light that alerts you to problems.
Hamstra Heating & Cooling, Inc.
Office:   (520) 629 -9833


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