I have an A/C that has recently starting dehumidifying a great deal, but it seems to be cooling just fine. This one 3-year old A/C generates about 1/2 gallon of condensate daily. The other two are running “normally” (dry).
As soon as it turns on, it starts dripping condensate into the drainage pan. Filters are clean. I can’t figure out any way to get to the evaporator coil - the unit seems to be completely sealed.
Seems like something I ought to investigate. Any troubleshooting thoughts are appreciated.
This exact thing happened to me this year. First, I would ensure that the draining conduit/PVC for the normal drain of condensate is clear. I just flushed some compressed air down the pipe to clear it. Used a tool specific to the job (CO2). Tried to use a vacuum on it, too. Neither worked. Finally called an A/C guy out.
Turned out the evaporator coil had a leak and needed to be replaced. Cost $4K to do it.
I’m going to say things I assume are already known, just in case, because sometimes what some of us think is common knowledge is not.
If this is a domestic central AC unit, like those with which I’m familiar, you should be seeing little or no moisture in “the pan”. The pan is an emergency catch, and drain off it is an emergency drain. If the unit is functioning properly, the condensate will drain from the evaporator catch, which has its own drain, usually into the sewer system for modern homes (built after the 1960s or so). IF there is condensate in the pan where you can see, it’s because the main drain is overflowing & probably needs cleaned out and/or addressed otherwise. Some folks make a blowout & bleach chaser an annual event. Some folks seem to be able to engineer it so it never needs cleaned… It depends on a number of variables what your options are…
True there is a main drain & emergency drain. If it is in the emergency drain then he main drain is clogged. Some will wire a float into the emergency pan to shut the unit down.
I just had this very problem on a unit at work. The “emergency” pan was filling up everyday even with a freshly cleaned out main drain. Turns out the plastic pan in the air handler itself was cracked, so the condensate was not making it too the clean drain and simply filling my emergency pan up (which has no drain, just a float switch to shut the unit down). It was a 5 hour repair for 2 techs because they had to evacuate the coolant and sweat some lines out and back in to get to the cracked plastic pan.
We aren’t waiting for it to go anywhere. We are observing it dripping into the drainage pan. Once it gets into the drainage pan it goes exactly where it should go. We’re certain nothing is clogged.
Dang that’s not very old for it to have failed. I would call the HVAC company you had install it to give you a diagnosis. If bad, see if they will make good and if not, ask them why they sold you a lemon coil that went out in 4 years.
I have a coil in a system I converted from R22 to R410A that’s 18 years old and is still working, even at the higher pressures.
Simply put, things aren’t built like they used to be. 20 years ago a unit was designed to last about 20-30 years. Now they are only designed to last 10-15. It’s fundamentally our society we live in today. Additionally the coils usually have a decent warranty but usually are parts only.
My house condensing unit it 24 years old. My indoor unit is 45 years old, I have myself been kicking the perverbial can down the road until it’s time to pick it up. I’m sure that time is coming. Hopefully then I can sell my refrigerant in it to offset most of the cost. I will also be re-doing the full system, duct work & all.
Just to reiterate, because your words make me think I’ve been unclear. Gloss over this if I’m just misreading.
Here is a photo borrowed from this site
If you’re seeing water dripping into the pan where the rust is, it’s not working right. That’s the “emergency pan”.
The condensate should be “disappearing” via the primary, as labeled in the pic, to the sewer. You don’t see anything dripping there unless you get inside the air handler/evaporator box (which it seemed like you indicated above you were unable to open, adding to my concern for lack of clarity on my part).
Be wary of your installation. I had an AC sub about 20 years ago that soldered together a drain pan and left a big gap at two corners effectively rendering it useless. The sub was very annoyed that I wanted it redone.
I also identified a problem with the drain. It was going ‘uphill’ to such an extent that it would have overflowed before draining to the sewer line. (It went over a rafter and needed to go through.) It would have absolutely not drained.
He passively aggressively ‘resoldered’ it and fixed the pipe. There was still light shining through the crack with a flashlight. At that time I suggested that he slowly pour 5 gal of water into it. If it should overflow he should pay for the damage. He did finally fix it. But I was astounded!
So, be careful. There might be some special engineering going on inside that system that may plague you later.
(A plumber on the same house built a closet around a water heater that could not be removed without tearing out the closet frame.) No telling what else was poorly done.
In this climate, all your AC units should be removing condensate constantly. If they aren’t, they are performing extremely poorly. But you won’t see how much they are removing in any reasonable unit because the primary drain pan is hidden internally to the unit. If you are seeing condensate, it sounds like your primary drain is clogged and it is overflowing to the emergency drain.
