For the life of me, I cannot figure this out. My air handler and heat pump were installed in 2006 and work great. For the first summer since I've owned the home, condensation started to not drain properly and is leaking onto the filter and onto the basement floor. The inside of this handler is spotless, including the drain pan. I took apart the PVC pipe and cleaned it out well, although I don't think it needed it. I still have major dripping! It does not look to me like it should be overflowing. It pours out of the hole circled below and then onto the floor and back into the unit and onto the filter. If it is coming out of this hole, why is it not going down the correct outlet to the pipe?! The only change point I can think of is that I purchased a box of filters on the web that had a pretty high MERV rating of 12. The fan seems to push air through it pretty easily, but I am wondering if this is somehow producing a vacuum that is not letting the water drain correctly. I removed the plugs pointed out below by the arrows to try and relieve this vacuum, but it did not work.

Any thought or advice? Last night, I cracked open a cold one and just watched in the basement. I can here the water build up in the pan as it makes this gurgling sound like some force is preventing it from draining, but it is on the verge of overflowing. Once the blower stops, all the water drains quickly. Some down the pipe, some out of the that hole. If the water is building up, I simply don't understand why it won't drain down the pipe. The water also drained when I removed the filter and left the cover off while the blower was running. hvac air-conditioning drain heat-pump condensation What you’re describing sounds like a combination of negative pressure in the compartment that the drain pan connected to and an incorrectly sized p-trap on the condensate drain. The depth of the t-prap has to be greater than the negative pressure in inches of water column of the compartment where the drain is connected to. A t-prap with insufficient depth, will prevent the condensate from overcoming the negative pressure which prevents draining until the fan stops.

Further information on sizing of p-traps for condensate can be found in this pdf article: Condensate Traps by Ronald F. Brusha. I know its a little late but I had a similar problem and my coils were stopped up with dirt. I cleaned my coils with coil cleaner and a tooth brush and rinsed with water. Make sure you brush with the grain on the coil so it doesn't get damaged. Then rinse with water. I repeated this process 3 times because it was so dirty. I used a pump up sprayer to rinse. After cleaning the coils everything is running smoothly.Browse other questions tagged hvac air-conditioning drain heat-pump condensation or ask your own question.What is a condensate drain line in central air units? A condensate drain is just a pipe that removes water from the evaporator coils. The drain pan or the evaporator pan is located underneath the evaporator coil. Should you install a trap in your condensate drain line? Yes, installing a p-trap to your condensate drain allows the condensate water to flow freely.

Without the p- trap installs, the air handler negative pressure will pull in the positive pressure air, this prevents condensate water from flowing. There is two or one condensate drain pan in central air unitsThe number of drain pan in central air units are depending on the location of the air handler unit. ac window unit trips circuit breakerAir handler unit in the ATTICWhen the evaporator coil and drain are located in the attic, it is recommended or required by local code to have two condensate drains.york rooftop air conditioning units The first drain pan is the known as primary drain pan and the secondary drain pan is known as the auxiliary drain pan. 5 ton ac unit goodmanThe primary drain pan is within the air handler; it is underneath the evaporator coil.

The secondary drain pan is located beneath the air handler; it is not within the close compartment. It purposes is to tell you the first primary drain pan is clog and you need to fix it. It will be drain in a place that is visual; it is a sign of warning to the homeowner. When an air handler in the basement; it does not required to have an auxiliary drain pan. Where is the condensate drain line on the furnace? A package unit on top of the roof needs to be drain purposely if it is outside; it is not a big deal. In split central air conditioner, the drain line is in the basement or in the attic. Look for a tube that travels from the air handler to outside. The tube could be white colored PVC pipe with P-trap. Some air handler unit will have a condensate pump to help move the water if gravity does not apply. How to install a condensate drain in central air units? Condensate Drain Pump in Furnace UnitDo I need condensate drain pump?If the condensate needs to pump a drain at higher level, it needs the condensate pump.

Condensate pump is useful when gravity is useless.Condensate pump will have a float to turn the pump on and some pump will have second float and safety switch to turn the central air units off, if the first float fails. How much water does a central ac unit produce?Each ton of central air conditioning in a climate with average humidity will produce 48 ounce of liquid (3 pints) per hour of operation. A 4 ton central air conditioner unit will condense about 64 ounce of liquid (12 pints) per hour of operation. The evaporator is removing more than a gallon of moisture per hour. Here is another way to determine how much water your central air units are producing, place a measurable container underneath the condensate outlet of your furnace and see how much it fill the container. Should I drink the condensate water?You should not drink the condensate water; however, it is useful for your garden or grass. What causes condensate water to leak? Leaks will occur when the evaporator coil drain line becomes clog.

Some central air unit will not have float switch at the pan to tell the central ac unit when the evaporator pan overflow with condensate water. That is when the leak becomes visual. Clogs condensate line can be caused by attic insulator, insect and airborne particle, such a pollen and dust. Algae build up in the lines, trap, and pans will clog the drain line. Drain pan can fails – overprotects it by Air handler does have secondary drain pan to protect the sheetrock. The primary and secondary drain line could clog and it will cause mess. The best solution is to install drain pan switch to turn off the condenser unit, whenever the secondary pan water level rises. It low voltage and expensive safety switch connection. The drain pan switch will be wire through the condenser unit. Ask hvac technicians to install it, if you have air handler in the attic. Condensate drain line needs maintenanceThe drain line needs periodic flushing to prevent algae build up and other growth substance. The Ac maintenance should be done by you or by your service HVAC company during annual maintenance or system tune up.