Editorial policy

Three rules govern every page on this site.

Manufacturer documentation first. Code meanings, reset sequences, part numbers, and specifications come from the manufacturer's own manuals and support articles, cited at the end of each page. Where third-party claims circulate that the manufacturer doesn't support, pages say so explicitly rather than repeating them.

No invented experience. Pages don't claim hands-on testing that didn't happen, and they don't fill gaps in the documentation with guesses. If a manufacturer doesn't define a code or publish a part number, the page states that.

Dated and corrected. Every page shows a "Last updated" date. If you find an error, use the contact page; corrections are made against the source documents and the date is updated.

Safety guidance (carbon monoxide, electrical work, refrigerant handling, space heater fire safety) follows CPSC, CDC, EPA, and NFPA-derived wording and appears on every page where it applies. Affiliate links never influence which codes or fixes a page describes — see the affiliate disclosure.