I was spinning it in reverse actually, but it would be enough to start the exhaust blower. It would also re-start pretty well for ~6 hours. It was probably the bearing. Also FWIW I have multiple carbon monoxide/air quality monitors and nothing tripped or alarmed.
Can you elaborate? I interpreted the same as the other comment that the blower fan just needed a hand start and kept going after the furnace started up. What you're saying only makes sense to me if the spinning the fan by hand allowed the furnace to start by bypassing the safety at startup, but wouldn't that mean that if the exhaust fan was stopped during normal operation (blockage etc) that the furnace would just keep going, dumping CO into the home?
From the description I thought that a degraded capacitor or lack of lubrication made the blower not start on its own, but the blower (and the whole furnace) would work if given a manual startup spin by hand.
The exhaust blower triggering a safety stop is normal when the blower should be blowing but isn’t. If the blower keeps spinning after it’s spun up manually everything is now working as intended. If it stopped blowing the furnace would go into safe mode again. Ask me how I know and I’ll tell you I had a broken blower on a cold winter before Gemini was a thing.
There are multiple continuous safety checks on such a system, and there was no risk of injury here. The fan itself is constantly monitored. Much more importantly, the pressure on the exhaust chamber is constantly measured (which can catch things like blocked outlets, a fan that might be spinning but not effective, etc).
If the exhaust fan couldn't maintain that negative pressure after the user stopped spinning it, the furnace would turn off again.
Their hack worked because the fan couldn't get the initial inertia up to speed (bad capacitor, dusty bearings, etc), but could maintain speed once it gets there. Have you never had an old home fan that would just hum when you turn it on but then work fine if you gave it the original crank? Same premise.
There was no risk here. If the fan didn't spin up to speed after that initial manipulation, and didn't constantly maintain the necessary flow, the furnace would have turned off again.
What is also true: If the induction blower/draft inducer/fan-thing/widget is not creating enough pressure differential to trigger the switch that exists just to monitor this condition, then the gas valve will not be opened to begin with. Therefore, there will be no fuel.
Without fuel, there can be no combustion. Without combustion, there are no combustion products. This lack of combustion products does not produce any particular danger. :)
Wonder how many AI deaths have occured that we dont know about(since they presumably died). With the adoption numbers we are seeing it much have happened already.
I'd be surprised if it was less than hundreds, or more than hundreds of thousands.
High hundreds of thousands feels like the upper limit before it would show up in statistically noticeable changes in patterns of deaths in some demographic.
High hundreds of individuals would still be "one in a million fatal errors over a few years", which seems better than I'd expect given I've personally had ChatGPT tell me that Solanum nigrum berries were "black tomatoes" (they're not usually fatal, but are a bit toxic, and no I did not eat them).
The most interesting part is that there is no direct line between someone's accidental death and a chatbot giving life-threatening advice.
Imagine one of the models that has "accidental-deaths-via-bad-advice" just slightly turned up, with the model-provider's intent being to kill 5% more people per year.
If you're paranoid (or a hawk), imagine a Chinese LLM that only offers fatal advice when queried English, or an American LLM that only offers fatal advice when queried in Chinese. Or American and Russian models which only offer up fatal advice when queried in German, Finish, or Danish.
“At its core, it's a small motor with a fan attached that has one primary job: to vent harmful exhaust gases out of your home before the burners ever kick on. This is the very first step in the heating sequence, and it's non-negotiable for a safe startup.“
The original comment was unclear whether the fan kept spinning while the furnace was running, or if all it did was bypass the safety and the fan didn't continue to spin while the furnace ran. They clarified in their response it kept spinning.
It seemed obvious to me that this was bearing stiction and that manually rotating it during the start allowed the fan to spin on its own after that, but I could be wrong and maybe the fan was dead entirely?
Yeah, that would be my assumption too (based on my admittedly incomplete personal experience where I got my furnace running by manually spinning my draft inducer motor, which kept spinning).
As exhausting the combustion products is a critical safety feature, I would be surprised if any furnace was designed such that it could possibly keep running if the draft inducer motor stopped. It seems like it would be trivially easy to make a circuit such that gas valves could only open if the draft inducer motor + fan wasn't spinning.
The exhaust blower not working triggered a safety that prevented the furnace from firing.
Spinning it bypassed the safety.
You likely inhaled a lot more carbon monoxide than you know.