I have an Amana where the HVAC coil drip pan must pool water to about a 1/4 inch before water starts to flow out the side of the pan.

I keep reading Standing water is not good to have because mold can grow. Or is this pooling water normal to have? Or should I do something to prevent that... ?

Unit is a split system in Phoenix, AZ.

  • Air handler in Attic
  • compressor is outside
  • Drip pans are usually designed to run dry, is the machine correctly level? – Solar Mike Sep 2 '20 at 2:43
  • @Solar Mike. There side drain is a quarter inch above the bottom. Water has to pool to that level before it starts to flow out. – jdl Sep 2 '20 at 2:55
  • Drip pans are supposed to be the secondary or back up drain. condensate should be carried from the internal coil drip tray to the outside of the house via pvc pipe . The pan under the unit should never have water in it unless the primary drain gets clogged. – Kris Sep 2 '20 at 3:17
  • The coil drip pan I am referring to is the primary. And the drain is via the side and the water must pool a 1/4 in before going out. – jdl Sep 2 '20 at 3:20
  • 1
    I will have to get that picture and info tomorrow... thx – jdl Sep 2 '20 at 4:19

I always put my pans in out of level so the drain is the low point. Once they are in it is possible to adjust them in some cases but can cause other problems. Stagnant water can be an issue and a way to prevent mold from growing in the pan is to add tablets made for hvac drip pans they last a few months and don’t cost very much.

Edit examples that can prevent problems even with proper drainage:

For example I just did a quick look amazon 6 tablets 9$ simpleair clean flow hvac.

A/c safe Ac-913 pan tablets 11$

Home depo carries some they last 6 weeks 1 or 2 tablets a year Takes care of most areas for the cooling season. You can keep them in there year round when heating they don’t dissolve.

  • I am curious why the 2 down votes I have a universal 608 and a 608 epa listening to change the ductwork after install can cause leaks or take the system out of level Most don’t have a clue on the laws or actual install procedures. With the information provided I gave a solution that will prevent mold and is recommend even without standing water required on large commercial systems. – Ed Beal Sep 3 '20 at 3:34
  • How do you install an internal tray out of level? Would it suffice to tilt the air handler so that the internal tray is sloping towards the drain hole? – Kris Sep 10 '20 at 16:52
  • Tilting the air handler in many cases caused other problems for example if the air handler is also part of the furnace you may trap moisture in the fire box putting a tray out of level is easy when building the system, but can be much more difficult after. most systems are in tight spaces trying to create a drain to the front or side is difficult because there is no access to the other side to raise and seal it. I always decouple ductwork from a furnace /air handler to reduce noise and this may allow for adjustments as most do this but sealing the back or side without access becomes the issue. – Ed Beal Sep 10 '20 at 17:42

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