Should the hole in my AC unit be closed to prevent water leaks, or is it meant to be open for ventilation purposes?
Asked by Bernadet Nieskens 
3 months ago
Last Updated: August 27, 2024
Hey, quick question – my AC is dripping water all over the garage floor. Should this hole be sealed or left open for ventilation or something?
I’m quite confident that it requires a plug.
You know what, there’s a possibility I could be mistaken. That could possibly serve as a backup drain outlet. ‘t you have a drainage pan?
Your main drain seems to be blocked. It appears that is the backup drain. Avoid blocking it. It is supposed to have its own pipeline. There are numerous videos demonstrating how to unclog your condensate drain for your air conditioner on YouTube.
Check if the closure or a sensor is installed to automatically shut off the unit when water backs up.
You can try using a wet/dry vacuum to remove any blockage in the pipe located next to the hole. If you feel suction in the hole, then it indicates a backup drain and it should have its own drain pipe.
I’m not sure if there should be anything connected to this hole. However, air conditioning units tend to leak water, hence the presence of a drain. If water starts coming out of this hole, it means your main drain is blocked and requires maintenance. It could also be due to a faulty installation.
Are you new to the property? The units should have multiple options for positioning the coil. Have you needed help with it recently? This area should be sealed, not left open as a vent.
Both drain pipes should be present – the primary one and the backup. The one on the left is likely clogged if water is coming out of the backup drain.
Try using a shop vac to remove the dirt from your main drain if it seems clogged. If you can’t do it yourself, you may need to call for service.
That hole is actually supposed to be plugged.
There seems to be a lot of misinformation in these comments haha. It’s possible that this is actually your primary drain and it was mistakenly connected to the secondary as your primary. The secondary drain should have a lip inside or be positioned higher than the other side, but this one doesn’t seem to have either. This could be the main issue. Nonetheless, that hole should have a plug, a safety switch, or another drain pipe. An exposed hole is never a good idea. There are various ways to address this.
I recommend routing your primary drain either outside or to a drain inside the house, depending on your HVAC setup. Then install a safety switch on your secondary drain that is connected to the 24v power to your thermostat. This way, if the primary drain gets blocked and triggers the secondary safety switch, it will shut off your thermostat, indicating a problem.
It’s not a vent. If that’s the secondary drain it should either have a pipe leading outside, a pipe connected to a pan with a float switch, or a sensor that can turn the unit off. Either way, it shouldn’t be left open.