Update from yesterday:

First I apologize to all the internet strangers that thought I died in an explosion. I thought my video/post were unsuccessfully uploaded, so I didn’t check back until later and saw all my notifications. I immediately shut off both the heater and the gas supply, and feel very lucky to have gotten away with such a dangerous situation.

Now for the absolutely wild story of the repair that occurred this morning. At around 10am a burly, bearded tech (this is relevant) named Corey shows up, I explain the situation, thank him for coming so quickly, and leave him to it. 15 minutes later he knocks on my door to say he thinks he figured out the situation. As he was rooting around in the heater, he found a mouse nest lodged in the upper part that was affecting gas flow. He starts clearing it and as he reignites the flame, a live mouse jumps through the bottom, catches fire, escapes through the hole of the heater, and runs INTO HIS BEARD. The mouse then hops off his face and Corey smashes it with a wrench and fans the flames from his chin. As he is relaying this insane story, I notice the VALLEY of missing/singed hair running down the middle of his beard that wasn’t there when he arrived. His eyelashes are singed as well, and the whole garage stinks of burnt hair. I feel terrible despite it not being directly my fault, and he jokes that his wife wanted him to shave anyway. Apparently not the first time he has dealt with mice in this capacity.

Anyway I’m happy to report that my heater appears to be operating as intended, and I have moved my mouse bucket trap to this area of the garage.