How we work
Methodology: How Our Guides Are Made
How our home-repair guides are researched, drafted with AI assistance, checked against manufacturer and safety sources, and reviewed again over time.
Last updated
The process, step by step
Research
Collect the manufacturer manuals, support pages and official safety guidance for the problem. Every source is opened and checked before it can be cited.
Draft (AI-assisted)
AI tools draft the guide from those sources in a fixed structure: quick answer, likely causes in order, steps, safety warnings and when to call a pro.
Check against sources
Every claim, number and step is checked against the page it cites. Anything a source does not support is cut.
Safety pass against official guidance
Steps are checked against official safety guidance and our hard limits for gas, electrical, refrigerant and carbon monoxide work. Anything past those limits becomes a stop line and a referral to the right pro.
Final review and approval
A last review works through a seven-point checklist: claims sourced, steps match the manual, safety checked, title and description accurate, diagrams checked, no AI writing artifacts, links checked. This review is AI-assisted. A guide that fails any point is not published.
Publish
The guide goes live on its scheduled date. Automated checks run on every build and block any page that breaks a source, safety or link rule.
Review at least every 12 months
Live guides are checked again against their sources at least once a year and before their season. A reader report or a broken source starts a review at any time.
Who does what
- Evrenus Fırat Polat, founder and Editor & Researcher, runs the site (LinkedIn). Evrenus sets the editorial and safety rules on this page and in our editorial policy, builds the diagnostic tools, and handles corrections and reader email. Evrenus is not a licensed technician.
- AI tools draft each guide from the sources collected for it. They also help run the review that checks the draft against those sources.
- Automated checks run every time the site is built. They block any page that breaks a source, safety or link rule.
No licensed technician writes, tests or reviews the guides today. If that changes, a guide will name the technician and their license, and only on the pages that person actually reviewed.
Sources we rely on
Every guide cites at least three sources, and at least one of them must be a primary source. Each source is opened and checked before it is cited.
| Tier | What it includes | What we use it for |
|---|---|---|
| 1, primary | Manufacturer service, installation and owner's manuals and official support pages; US government agencies such as the Department of Energy, the EPA, the Consumer Product Safety Commission and OSHA; standards and safety bodies such as NFPA and UL | Steps, specifications and safety rules |
| 2, supporting | Utility safety pages, university extension services and trade associations | Background and context |
| 3, costs only | Named cost surveys, always cited as "according to" the publisher | Cost ranges, never procedures |
We never cite forums, Reddit, YouTube, other repair blogs, Wikipedia or answers from AI chatbots.
Inline numbers such as [1] point to the Sources list at the end of each guide. The list shows the publisher, the title, a link and the date we accessed the page. We write in our own words. We don't copy manual text, tables or figures, and we don't embed manufacturer images or PDFs in our pages. When a general source and your model's manual disagree, the manual wins.
How we use AI
- AI tools draft the text from the sources collected for a guide, in a fixed structure: quick answer, likely causes, steps, safety warnings and when to call a pro.
- AI tools help check the draft against those sources, claim by claim, and flag anything a source doesn't support. Unsupported claims are cut.
- An automated check scans every page for leftover AI phrasing and unfinished placeholders.
- AI is never used to invent sources, experiences, test results, quotes or reviews. If no source supports a fact, the fact is left out.
Every guide carries a short note that says how it was made, with a link back to this page.
How diagrams are made
Diagrams are original line drawings made for this site, with AI assistance, from the parts layouts shown in manufacturer manuals. They are simplified on purpose. Numbered callouts mark the parts a guide talks about, and a legend under each drawing names them. We don't copy manual figures and we don't use photos. Your unit may look different, so treat the drawing in your own manual as the reference for your model.
How the diagnose questions work
Each set of diagnose questions covers one symptom, such as a furnace that won't turn on. It asks three to five short questions and ends with one to three likely causes. Each cause links to the matching section of the guide. Every question has an "I'm not sure" answer.
Question sets for gas appliances include a safety check first. If you smell gas or a carbon monoxide alarm is sounding, the tool stops and tells you to get out and call for help. Each stop screen cites official safety guidance.
The questions run in your browser. Your answers are not stored on our server. If analytics is turned on, it counts which answers people pick so we can improve the questions, as our privacy policy explains.
How the repair-or-replace calculator works
The repair-or-replace calculator gives a rule-of-thumb answer, not a quote. You enter the age of the unit, the repair quote and, if you have it, the price of a new unit. The tool compares them with typical lifespans from published industry sources and with a small set of documented rules, such as how much of the expected life is used up and how the repair compares with the price of a new unit.
A few answers are fixed. A leaking tank on a tank water heater, for example, always points to replacement. Every lifespan and rule on screen names its source, except one: the "half the price of new" rule (replace once a repair costs 50% or more of a new unit) is our own editorial rule of thumb, and the tool labels it that way. The tool has no built-in prices and never estimates costs for your area.
How error codes are handled
Error-code meanings come from the manufacturer's own manuals and support pages. We write them in our own words and link the source for each code. A code gets its own page only when there is enough sourced, model-specific help to make the page useful. Other codes appear only as a row in the table for that brand and appliance.
When a guide tells you to call a pro
Every troubleshooting guide has a "When to call a pro" section. It lists the signs that mean you should stop, such as a gas smell, a scorched part, a leak from the tank itself or a breaker that trips again. It names the trade to call: a licensed plumber, an HVAC technician, a licensed electrician, an appliance repair technician, your gas utility or the manufacturer's service. It also gives a short description of the problem that you can copy and send to the technician.
Hard limits
- Gas. Guides cover checking the gas valve position, and relighting a pilot exactly as the appliance label says. They never cover cleaning or replacing a flame sensor or igniter (furnace manuals such as the Bosch 96% AFUE installation manual mark both for qualified service technicians only), gas line or connector work, gas valve replacement, pressure or orifice adjustments, or venting changes. If you smell gas, leave the area and call 911 from a safe place well away from the leak, as the Pipeline and Hazardous Materials Safety Administration advises.
- Electrical. Guides cover breakers, fuses, user-replaceable plug-in parts and low-voltage (24-volt) thermostat wiring with the breaker off. They never cover panel work, 120- or 240-volt circuit wiring, or capacitor work. For those, a guide describes the symptom and sends you to a pro.
- Refrigerant. Guides cover the signs of low refrigerant and cleaning coils and filters. They never cover charging, recovery, brazing or leak repair. Federal rules under Section 608 of the Clean Air Act prohibit intentionally venting refrigerants and require certification for technicians who service equipment that could release ozone-depleting refrigerants.
- Carbon monoxide. Guides cover alarm placement, testing and symptoms. They never cover heat-exchanger or flue repair. If you suspect CO poisoning, get outside to fresh air right away, then call 911, as the Consumer Product Safety Commission advises.
- Hot water and pressure. Guides cover testing the temperature and pressure relief valve as the water heater manual describes, and draining or flushing a tank with the power or gas off. They never cover replacing that valve on a system under pressure.
The full table is in the safety scope section of our editorial policy.
How guides stay current
- Every live guide is reviewed again against its sources at least once every 12 months.
- Seasonal guides are reviewed before their season: heating and water heater guides by September 1, cooling guides by April 1.
- If a guide's last review is more than 120 days old on its publish date, it is reviewed again before it goes live.
- Cited links are checked automatically on a schedule. A broken or changed source sends the guide back to review.
- Reports from readers start the corrections process at once.
What the "Updated" and "Reviewed" dates on a guide mean is explained in the updates and dates section of our editorial policy. Errors we fix are listed on the corrections page.