Guides

How to find and read your furnace's flash code

Where the LED is, how short vs. long flashes work, and why the same count means different things on different brands.

Furnace in lockout: what it means and the one safe way to reset it

Soft vs. hard lockout, why furnaces lock out on purpose, and why repeated resets make things worse.

What to do if you smell gas

The short version: leave first, call from outside. The full checklist.