Let us help you identify that mysterious object you’ve found.
Currently in CHALLENGE mode: If you've got something obscure knocking about, post a picture, and let's see how we do. Please prefix such posts with "CHALLENGE:" so we know we've got a fighting chance.
What's this device (circled in blue) that's attached to my furnace? It recently got replaced and I forgot what the HVAC technician called it, or what its function is.
I do rember that they said to put some vinegar in the U-bend (circled in red) once or twice a year. I forgot to ask why this is necessary, but I'd guess that it tends to collect moisture, and the vinegar will prevent mold?
Hey OP, I was cleaning out condensate lines at work the other day and thought you may want to see a bad case of build-up:
It's a condensate pump. When you run your AC, that's the thing that pumps the condensation that is produced out of your house.
That's the condensation pump. Without it, your furnace would build up condensation.
It wouldn't build up, it would just spill onto the floor. Houses with drains near the furnace don't need these pumps.
It builds up condensation anyway; this just removes it
Also, it's not really necessary to treat with vinegar, but it is very helpful. Over time, a substance called Zooglea grows in the line and can cause clogs.
And a bunch of other microbes too. A single species may dominate the population, but it’s highly likely that there are several other species hanging around as well. Adding some vinegar will make the conditions more challenging for most of them, so many will just die while others may struggle and grow very slowly.
In ELI5 speak: Gross bugs growing in there. Add vinegar to make it a bit nicer.
Condensate pump. It fills up with water and then pumps it up that pipe and outside somewhere.
Condensate pump?
Googling the brand name on the product shows "condensate pump" as the result.
Unrelated, a clean looking install.