An HVAC repairman can usually fix this for the price of a standard service call. Dirt, slime and algae tends to build up in the condensate drain outlet and/or pipe, causing the drain to clog, water will overflow and run down between the floors and walls. Cleaning isn’t difficult – wipe away what’s visible, run a bottle brush instrument down the pipe, blow it out with compressed air, chemically disinfect/kill the algae and rinse out the pipe, then put some time release algae inhibitor tablets in the condensate drain pan for long term (couple of months) relief. Most condensate drain pipes are PVC plastic and worst case a section can be sawed out to get access at a clog further down the pipe and replaced.

> They said the water is coming from the condensation pipe that travels throughout out units. It serves us all.
If the HVAC technician says your drain pan and drain is fine, then take the matter up with your condo association as a common infrastructure maintenance responsibility.

> mine hasn’t been cleaned in several years.
Yours may need inspection and cleaning anyway. You’ll save money on the lower electric bills when the system is tuned up and running at optimum efficiency.

Please post back when you find the problem and how it was repaired.

The small copper pipe carries the relatively “hot” (or at least warm ~100F) high pressure liquid coming from the outside compressor/condenser unit to the air handler evaporator coils in the attic. See Figure 1.6 on page 8 and Figure 1.9 on page 10 of the “PRINCIPLES OF AIR CONDITIONING” as to why the liquid line from the condenser is hot in relative terms (100F).

Also see “How does air conditioning work?” by Austin Community College. The small “hot” copper liquid line in question runs from the Condenser (#2) to the Metering Device (#3) in the Austin College diagram. The Metering Device is also known as an Expansion Valve which flashes the high pressure hot liquid refrigerant refrigerant to a low pressure cold (20F) gas for circulation in the evaporator coils. The larger copper pipe is the return refrigerant gas line that is remains somewhat cold after leaving the evaporator coils and must be insulated to avoid condensation and sweating all over the attic and inside the walls.

If you’re *very careful*, a soft long bristle brush can be used to help remove the insulation. Go easy and check your progress because the fins are easy to bend/fold over.

The next issue is to determine how insulation is getting blown onto the coils. Do you have a break in the plenum or ductwork? Has an insulation panel inside the air handler become loose? Is the air filter seated properly? The color and texture (pink, yellow, white, black; coarse or fine) of the insulation is usually a good indicator of where it originated.

Should I be using a cleaner on the outer dry part to improve circulation/performance?

Very nice site with the best information I’ve seen. Thanks for making it available.

“My recommendation is to call a HVAC company to inspect your unit for a bad control valve, check the thermostat and condition of the coils. My bet is you have a problem with the control valve.”

To clarify, I believe you have a problem with the water control valve or the control circuitry (relay board) that operates the valve.