How much of the model number is necessary?
My range shows number 30-2242-00/10343-855057_ (Last digit has been scrubbed away.)

Generally the first advice I see on the internet seems to be to replace the Hot Surface Ignitor.

My HSI seems to get mighty hot. It lights the room with the bottom panel out of the oven.

What's the next likely problem?

I wish I understood how this oven works. I see that the oven knob does not directly control the gas. It has two electrical connections and a copper tube entering it which must be from a thermocouple or thermostat.

Apparently the knob just switches electrical current on/off and the gas valving operates off of that current down in the oven?

If that's right so far, then there must be a lot going on down in the oven. I presume there is a heat sensor that selects the HSI unless it can tell the oven is already ignited? I guess if the oven is already ignited then the current from the oven knob operates a gas valve according to the thermostat telling the knob to turn the current on and off?

Anyway, much as I'd love to understand it all, I just really need to fix it. But I wonder if there is a functional diagram or schematic or something that would help me reason my way through the diagnosis?

TIA