What are the factory settings for a standing pilot furnace equipped with a bi-metal fan/limit control?

The correct choice reflects the typical factory settings for a standing pilot furnace with a bi-metal fan/limit control system. In such systems, the fan on setting indicates the temperature at which the blower will start operating to circulate air, while the fan off setting designates the temperature at which the blower will stop running. The limit cut out represents the maximum temperature at which the furnace can operate safely before shutting off to prevent overheating.

For a standing pilot furnace, the settings of fan on at 125°F, fan off at 80°F, and limit cut out at 200°F are common because they provide a balance that allows the furnace to operate efficiently while ensuring that it does not exceed safe temperature limits. This setup also helps maintain an optimal indoor climate by keeping the furnace running long enough to distribute heat effectively but not so long that it risks overheating, which could lead to equipment damage or safety hazards.

In contrast, the other provided options involve temperature settings that either exceed typical safety ranges or are not recognized as standard factory settings, thus making them less suitable for typical HVAC applications.