Jacksonville's Duct Cleaning Specialists
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(904) 716-9325
(904) 716-9325
"T" connector
3/4 PVC
Existing PVC
Condensate Line Water Damage:
Many homeowners are unaware their air conditioning unit can become a source of water damage to their home. The air conditioner condensate line can become blocked, causing water to back up into the unit and overflow. This can be easily avoided if the unit is properly installed and maintained.
From State Farm Insurance --
If the air handler is in your home it will ruin carpets and expensive wood floors. If it is in the attic you will most likely have to replace the ceiling(s) in the home and insulation in the attic.
If water damage is left unchecked and moisture persists for more than 48 hours Mold begins to grow at a rate up to 33 MILLION plants in a 24-hour period. A condensate drain pan is built into the unit by the manufacturer and is located below the evaporator coil. The air handler fan blows air across and through the evaporator coil, and the refrigerant changing state from a liquid to a gas as it loops through the coils cools the air as it passes by.

Figure 1: Evaporator Coil, Drain, Pan
The warmer house air making contact with cool air causes the water vapor (humidity) in the air to condense to liquid and collect on the evaporator coil. The water (also called condensate) then drips into the condensate pan under the evaporator coil. There is a condensate line connected to the outlet hole in the drain pan and exits out the front of the air handler. This condensate drain line is piped to either a floor drain or to the outside. Some times instead of a pipe, the mechanical contractor will use a hose for the condensate drain line.

Water damage can occur when the condensate line clogs. As air passes over the wet coils bacteria and mold spores attach to the droplets. The water in the drain pan and drain is now contaminated with it and algae or debris forms a jelly like mass inside the drain causing the water to back up into the condensate pan. The condensate pans are typically only about an inch deep so it doesn't take long for the water to start overflowing and spilling onto the floor, inside the return insulation board, or the ceiling below.

Many times blocked condensate drain lines are a problem at the beginning of the cooling season, after the air conditioner has been idle for months. As mentioned above, if condensate water has been sitting in the drain pan or drain line, algae will grow and block the line. This is especially true in humid, southern climates. When the weather turns warmer, and the air conditioner is turned on, the evaporator coil begins to discharge condensate water, and the algae blocking the condensate line causes the water to overflow onto floors, ceilings, or attic insulation.

Proper Drain Line Size:
The 1996 International Mechanical Code and the 1995 CABO One & Two Family Dwelling Code require a minimum size condensate line of 3/4" from an air conditioning unit.

Preventive maintenance should take place just before the beginning of each cooling season before the air conditioner runs for the first time.
1. Make sure the drain line slopes down from the air handler all the way to the floor. It should not have any section that is level where water will settle. Standing water can facilitate algae growth.
2. Begin by checking to see if the condensate line is partially blocked. Pour water down the pour spout (if you have one). The water should flow freely out the other end (usually near the condenser). If it drains slowly it is more than likely near being blocked. NOTE: Older systems may not have a pour spout (or "clean out") or Overflow switch. It is recommended that you ask your local AC Company to install one the next time he is out to your home. If you are mechanically inclined you can install your own for a few dollars instead of $75 plus. Your PVC drain should be inch. Go to your local Hardware Store (the plumbing section) and buy a "T" connector for $1.30 (figure 2) a piece of PVC, PVC glue ($3), and a Cap (59 cents).

* Refer to Figure 2
* Cut out a inch length piece of the old PVC drain so you can install the clean out. BR> * Rub the PVC glue on both the inside of the T connector.
* Push the lines into the T connector it will dry in 30 seconds so make sure the T connector is pointing up.
* Cut a 3 to 4 inch piece of PVC, apply the PVC glue to the outside and to the inside of the T connector and fit the piece to the "T" connector.
* Push on the Cap DO NOT GLUE THIS, as it will be taken off every time you use the clean out.
3. In addition to yearly maintenance checks, regularly check for water or water stains on the floor or ceiling below the evaporator coil. This will help alert you to a potential problem with the drain line.
4. To prevent drain clogging, pour cup of bleach or white distilled vinegar in the pour spout 3 times during the warm season when the Air Conditioner is working. It will kill algae and bacteria. NOTE: DO NOT pour bleach in the pour spout in cold weather when the heat is working. The bleach needs to mix with condensate otherwise it will gradually eat away at the PVC.It is recommended that you use the vinegar every 3 months

If you don't have a pour spout and you did not install one as shown above.
Remove the bottom cover of the air handler (either or 5/16 hex nuts) and pour a half and half solution of water and Clorox and 4 teaspoons of white distilled vinegar into the drain pan. If you can see any other debris remove it or use a scrub brush. Flush with water liberally. Replace the cover.