What is on the side of my furnace?

Condensate drain for your high efficiency furnace. Your A/C A coil might be tied into it to. Some setups might include a condensate neutralizer and/or pump.

edit: For maintenance if it clogs which is rare and far between, I use a shop vac followed by a vinegar flush.

bubuski wrote: ↑ Condensate drain for your high efficiency furnace. Your A/C A coil might be tied into it to. Some setups might include a condensate neutralizer and/or pump

Interesting. Our furnace is pretty old, estimated at time of purchase (sept 2017) to be 15-17 years old. Would if be normal to be considered high efficiency back then? There's definitely no pump as there is no power to it, just the drain lines and line up the the exhaust pipe. The A coil has a separate drain line that does not connect to this unit. 1 clear drain line comes from the humidifer and the black line I can't determine but looks to be heading in to the furnace at the blower. Without opening more of it I can't determine what it is connected to.

Other than ensuring the drain lines are clear and drain which I have done a few times, is there any other maintenance I should be doing?

Yes high efficiency technology (over 90% AFUE) was available and were sold in residential units. My old Goodman furnace from 1995 was a 93% high efficiency unit.

The pump is usually added if a floor drain is not available and the condensate will have to be pumped up to a utility sink or other accessible drain that is not at floor level.

I think that black box is your condensate neutralizer. Check if it has limestone gravel on the inside, as long as is not clogged it's acid neutralizing properties should last the life of the furnace. Although the limestone is sold separately as a replaceable kit. The main concern of the acidic condenstate water is your house drain pipe, if it is PVC then you don't actually need the neutralizer but your city might have it mandatory to protect the city drain lines(hazardous waste category?). My old 93% furnace had a condensate neutralizer, the replacement 97% furnace did not get a condensate neutralizer. I also now have a 96% condensing tanklesss which does not have a condensate neutralizer. It could have been the installers cutting corners and I've always thought about adding one back in.

For your humidifier, it does not need to go through a condensate neutralizer because its waste water is not acidic. It might have been added if it was easier to connect there rather than running an extra tube all the way to your floor drain.

Just make sure the tubes are clear of debris. That section that connects close to the inducer motor is one of the more common places that clogs with gunk.

I don’t know. But you shouldn’t be storing flammable items near your furnace.

That drain hose looks like it is kinked

Gee wrote: ↑ That drain hose looks like it is kinked

I adjusted it right after I took the photo fortunately.

Maplesugar25 wrote: ↑ I don’t know. But you shouldn’t be storing flammable items near your furnace.

True. I wasn’t paying attention to that when I brought the paint cans in before winter set in. I’ll definitely move them.