[Bwanajim]

Originally Posted by jayerose

Heard a new one last week...a friend's drain line was clogged due to a dead frog who got stuck in the drain; their AC started overflowing into the house while they were gone for a few days...of course, they came home to a mess.

Does anyone have a screen or flappable door over the drain line?

Two things. The overflow pipe is not properly installed. It should come up, have two 90s together and go back down an inch or two. in other words have it make a quick U-turn
2) get in the habit of pouring some vinegar down your drain pipe that’s next to the AC every few weeks. That removes any slime buildup.

[Topspinmo]

Originally Posted by retiredguy123

Some condensate drains are "trapped accidentally" by the way the water is routed, but there is no code requirement to design a trap into the drain line.

Anytime goes down and back up it’s trap

[retiredguy123]

Originally Posted by Topspinmo

Anytime goes down and back up it’s trap

I agree. But, some HVAC systems do not have a condensate drain that goes down and then up. They just drain in a constant downward direction, with no trap. My only point was that a trap in the condensate drain is not needed or required.

[retiredguy123]

Originally Posted by Steve

I've found over the years that the float switch in the HVAC works about as well as the rain sensor on my irrigation system...NEVER! I just check my drain line once a month by pouring hot water through it.

I agree. But, some people (not me) pay an HVAC company to maintain their system every 6 months or a year. If you do that, I would require the company to test the float switch for proper operation as part of their regular "tune-up".