PSA: Furnaces Have Fuses ...

... or at least ours does.

So back to the humidifier project: After Celeste's 4:00 a.m. feeding, she needed a diaper change, so I took care of that and decided that — since I'm trying to get up early so as not to create too great a disparity in sleeping habits on the days I have to be at work for 4:00 a.m. vs. the days I have to be at work for 8:30 a.m. — I'd go futz around some. After paying some bills and entering receipts into Quicken, I started thinking about the humidistat and decided to at least prep the wiring.

I figured I'd cut what I needed to size, strip insulation, and maybe connect the relay to the humidifier (leaving the circuit from the relay to the humidistat and the humidifier to the humidistat open). All was going pretty well until I connected the wire to the relay that would run to the humidifier.

The fan was running as I doing this and I didn't give it a second though, but, when the bare tip of the relay-connected wire brushed the aluminum duct housing and a nice blue spark popped out, I got very aware of the fan ... or at least of the fact that it was no longer running. At this point, Evelin heard floating up through the duct work: "Oh no! Oh no! Oh no! Oh no! Shit! Shit! Shit!"

I checked the circuit panel and nothing was tripped. I ran upstairs and the display on the thermostat was dead. More colorful language. I tried switching the circuit breaker and the disconnect on/off to no avail. I then dug out the owner's manual. Actually, I couldn't find the owner's manual for the furnace (everything else that was installed along with it had a booklet in the folder, just not the furnace), but I did scan the thermostat's guide.

It first suggested checking the breaker panel. I'd done that. Then it said check the fuse. We have breakers not fuses, so I ignored that. It then ran though a few other things that didn't seem to apply or work.

I figured things were already shot, so I opened up the panels on the back of the furnace to see if any circuitboards were obviously scorched. This is when I find a little ATC slot-type fuse on the circuitboard — and it is as black as can be.

I go upstairs to break the news to Evelin and Celeste that they'll probably want to stay in bed because I broke the furnace. Since I was only 6:30 a.m., I decided to take a shower and to get ready for the day before trying to find a new fuse (given the time, what else could I do?). At 7:00 a.m., I'm in Home Depot looking at their pathetic offering of fuses — no 3 ampere ones. I head over to North Brentwood to a plumbing supply place I've passed on my way to work; again no 3 ampere ones. Then I start cruising around Brentwood, Edmonston, Hyattsville, Riverdale Park, Bladensburg, ..., stopping at about five plumbing, heating, and/or auto supply stores before finding one that had the fuse I needed and that was open.

Back home a little after 8:00 a.m., I snap in the new fuse and rush upstairs to find the thermostat still dead. I run back downstairs, remembering that I'd forgotten to reset the disconnect; back upstairs, it's still dead. I run back downstairs, remembering that there's a kill-switch on the furnace and it won't start if the back panel is off; back upstairs ... success! I can stop worrying about a frozen wife and baby!

Probably if I remember to turn the furnace off before setting up the humidistat, I'll probably be okay, but I am a bit worried ...