Why’s to clean out AC drain line safely

I did both at the same time. Worked for me.

Correct answer. I have a lot of issues with it down here. Mine clogs at the very end of the drain pipe as they put a 45 deg fitting on there. Clogs in that fitting.

But, after I finger that thing clean, I put my shop vac on there and let it suck the muck out for about 10 mins. Then once its done, I pour a gallon of white vinegar down the pipes to help prevent it from happening again


My shop vac has a much bigger hose so I just use some duct tape to wrap around the opening and make a good seal. Its stupid but it works

If clogged and not draining, yes then vacuum if possible if plumbed to the outside. In LA that’s difficult as many are plumbed in a vent stack drain in the attic so there is no open end to attach a vacuum to - you would have to cut the condensate drain line closest to the vent stack to vacuum and then patch when finished - or re-plumb it with a vacuum port.

For maintenance, 1 or 2 cups of vinegar monthly poured down the condensate drain line vent tube works. I did use bleach, but no longer, for maintenance - thought is that the caustic nature of bleach (fumes) can potentially damage the evaporator coil over time causing refrigerant leaks. Not my thought, just comments on the web from HVAC professionals. However, in the past when I did have a clogged condensate drain line, I always poured bleach down the vent tube and in every case it cleared the clog - fortunately the clog was always downstream of the condensate line vent tube.

If you have clog in the condensate drain line between the vent tube and primary drain pan then you might have rig up a port next to the evap coil cabinet to either vacuum or blow in compressed air or carbon dioxide.

Of course, putting anti-slim, algae, tablets in the primary drain pan at the beginning of the cooling season will take care of all that - tablets last 6 months? Anyway, techs do that with annual maintenance plans but a DYIer can do that if they don’t mind opening the evap coil cabinet and resealing it.

TLDR: couple cups of vinegar down the condensate line vent tube monthly during cooling season - I start in March, maybe end in October.

Thank you !

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My shop vac has a much bigger hose

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I put a large funnel in the pvc drain pipe then use the shop-vac in the funnel.

Seals it up pretty good.

white vinegar followed by warm water a few minutes later.

Thanks

Vinegar and water?

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I put a large funnel in the pvc drain pipe then use the shop-vac in the funnel.

Seals it up pretty good.

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Good tip. Thanks. I will give that a try next time. And there will be a next time.

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But why? I ask again, why the hell would they do that and how does that even work? Where does that water go out the roof?

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It goes to yuour main drain line. There is a tattle tale pipe that is routed to the outside of your house from the drain pan