I’ve now had four dehumidifiers die in quick succession, and I’ve learned that the manufacturers have got down the art of making coils so thin that they tend to spew their ozone-depleting refrigerant not long after the warranty expires. (One should still be under warranty but I misplaced the receipt.)
Unfortunately, I don’t have a good way to use only gravity drain, so I’ve been buying more expensive dehumidifiers with built-in pumps. My old (nearly 30 year old!) dehumidifier that I never threw away for some reason but doesn’t have a pump has been sitting here doing nothing for almost 20 years.
I bought what I thought was a better dehumidifer from AlorAir, but when it arrived I found that their warranty statement on their Amazon site was misleading. They claimed that Amazon didn’t give them enough room to accurately represent the warranty. 
I made them eat a return based on the fraudulent listing and gave them a one-star review for their fraud (which Amazon in their infinite wisdom have chosen to leave unpublished), and asked for advice on Mastodon.
The advice I got from @djb_rh was for AprilAir; more than twice as expensive and not a particularly better warranty (but at least represented honestly), and it doesn’t include a pump. But at least it has a reputation for longevity.
I finally realized that if I needed a separate pump anyway for the AprilAir, I might as well try using it with my old dehumidifier! I would just need to 3d print some funnels to catch the main drop and the overflow, and engage with the bucket-present-and-not-overflowing switch.
Fortunately, I tested the pump with tap water before trusting it to run indefinitely. That let me know that the line was clogged. After I blew it out with compressed air, it ran fine.
Maybe after the basement humidity levels are back down to my preferred dessicated, I’ll see about wiring the emergency cut off switch on the pump to the bucket presence switch on the dehumidifier. I do hesitate to disassemble a working dehumidifier, though! 
Thanks to a mistake in my ABS profile for that printer (which I’ve only just recently started using ABS in) of not enabling part cooling, the overflow funnel printed with a bit of a defect that looked ugly but didn’t affect its function. I didn’t waste plastic with a re-print, but I’ve fixed the profile for other parts.