Red Seal Plumbing Practice Exam 2026 - Free Red Seal Plumbing Practice Questions and Study Guide

The white button on the front lower left corner of a furnace equipped with a fan/limit control is typically used to manually turn the fan on. This is useful in situations where the fan may not automatically turn on, such as during a power outage. Option A is incorrect because while the button may reset the system, that is not its primary purpose. Option C is incorrect because adjusting the temperature is typically done through a thermostat or control panel, not a physical button on the furnace. Option D is incorrect because the button does not indicate the system status, it simply toggles the fan on or off.