Originally Posted By: jpeck
This post was automatically imported from our archived forum.
While the IRC is written differently than the Florida Building Code, it does end at the same intent. A drain pan is required under ALL evaporator coils.
There should be a primary condensate drain line from the primary condensate pan connection (the lower of the two openings which are side-by-side) and there should be a secondary drain line from the secondary condensate connection (the higher opening right next to the primary condensate opening). The secondary drain line should run to the secondary drain pan under the furnace or air handler which has the evaporator coil.
The secondary drain pan should then either be drained (the preferred method) to the exterior with the discharge in a conspicuous place to warn the occupant that the secondary drain pan is in use (which indicates that the primary drain is clogged), or, install a safety cut-off switch in the secondary drain pan to cut the system off when water begins to collect in the secondary drain pan. This way, when the a/c technician comes out to find out why the a/c is not working, they see water in the secondary drain pan and know what the problem is. And the water does not overflow and ruin the ceiling - the reason for all of this.