Gemini almost killed you.
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.
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.
Helping something start is not likely to ruin your day (unless you get caught in a rotating part)
When GP spun the fan it fooled the computer into thinking it was running and continuing the ignition sequence. It may be that once the burners got everything hot there was enough airflow from the thermals so they didn't have a buildup of CO. Or were just lucky.
[1] The motor is usually generic but has a proprietary bracket, which was a $1500 lesson last year
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. :)
"Spinning it to bypass the safety" is not a thing.
Please don't spread FUD.
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.
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).
“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.“
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.