How can I unclog a continuous drain in a portable air conditioner?

Question

I bought a 10K SACC refurb Danby portable AC. It comes with a transparent draining hose, one drain opening at the bottom, and a 'continuous' opening in the middle.

Regretfully when using the middle continuous opening I get tank filled error in half an hour.

Bottom opening works fine but I have to put the conditioner on a stool to drain into a bucket. So cool air goes to the ceiling rather than at me, which is not ideal and exhaust hose is a bit stretched.

I found few ideas on internet, but would like hear expert opinions to minimize risks and potential damage to the unit and apartment.

I have already tried to blow air in with hose and mouth which did not work. I am afraid to suck air out to get poisoned, it is a refurb and who know what solutions were tried before I got it.

I have neither air pump nor wet-dry vacuum. I have a canister one (Miele C3) and small stick vacuum. Maybe there is a way to use them somehow?

At the moment I think to try inject some vinegar into the opening with 5 cm3 surgical syringe.

What do you think?

I suspect chemicals or bleach would be more effective yet in the same time more risky for the apartment, furniture or the unit.

Answer 1

Some repeat vacuuming of both regular and continuous drain openings helped to fix the continuous drain feature.

Perhaps, injecting vinegar also contributed.

This particular unit also requires a little tilt forward to make continuous drain work.

While it is recommended to use a wet-dry shop vacuum (combined with peroxide or vinegar treatment), I only have regular household vacuums. So, I decided to pre-dry the unit and then vacuum it.

1. I gravity drained the AC unit by tilting it almost to 45 degrees (do not try alone unless very strong). Obviously, I unplugged the device before all these manipulations.

2. I used a hairdryer on high heat for 30 seconds, then pre-vacuumed the AC openings with a cheap bag-less hand vacuum with a washable HEPA filter and transparent canister/cyclone using a drain hose. A small, but not negligible, amount of water was extracted. The hose-to-vacuum connectors were fashioned from plastic bottles.

3. I plugged in the AC again and let it run in ventilator mode for a few hours to let it dry out.

4. Only then did I apply a powerful canister vacuum with a heavy dust bag for about two minutes, even though some experts believe that 1 minute is enough.

The continuous drain started working after that.

I did not try to disassemble the unit for further inspection, due to previous experiences with my dehumidifier cleaning.

Note: I do not have a strong attachment to either of my vacuums and have a spare old mid-size vacuum somewhere. Otherwise, it is best to invest in a decent wet-dry shop vacuum.