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The fine print study: warranty and manual rules in 654 products

We read the maker's documents for every product guide we publish: manuals, spec sheets and warranty pages. This study counts what those documents say in the fine print, across 654 products in 43 categories. We did not test any product; every figure below is a count of maker statements our research notes recorded, each with its source link.

Published 24 September 2026 · 1479 data points from 671 maker documents · Download the data (CSV) · How to cite

Headline findings

Each finding counts products, not mentions, and only counts a statement when our notes tie it to a maker document's URL. Notes record what the researcher needed for the guide, so the counts are floors: a product not counted may still have that rule in its manual.

1. 334 of 654 products have a warranty term recorded from a maker document. For 95 of them the longest term stated is one year or less; for 76 it is five years or more, including lifetime. The most common longest term is 1 year (95 products). (n = 334 of 654, 51%)
2. 19 of those 334 products name more than one base warranty term; the data lists each term with its source. (n = 19 of 334, 6%)
3. 119 products' warranty terms cover only the original purchaser or say the warranty cannot be transferred. (n = 119 of 654, 18%)
4. 88 products' documents limit the product or its warranty to household or personal use. In 62 of them the warranty excludes or shortens commercial, rental or professional use. (n = 88 of 654, 13%)
5. 73 products' warranty terms exclude or void coverage after unauthorized repair, opening or modification. (n = 73 of 654, 11%)
6. 32 products tie a longer or activated warranty to registering the product. 14 of them set a deadline, from 10 to 120 days after purchase or delivery. (n = 32 of 654, 5%)
7. 24 products' warranty terms apply only to units bought from the maker or an authorized seller, or exclude units from unauthorized sellers. (n = 24 of 654, 4%)
8. 98 products' maker documents set a maintenance task with an interval (for example weekly, every 3 months or after each use). The most common tasks are cleaning (39 products) and filter cleaning or replacement (23). (n = 98 of 654, 15%)
9. 37 battery products state a temperature range for charging. For 32 of them every range we recorded starts at 32 °F (0 °C) or warmer. (n = 37 of 654, 6%)
10. 95 products state an operating temperature range. (n = 95 of 654, 15%)
11. 55 products' documents give a minimum clearance or distance, such as space around the unit or distance from combustibles or from a house. (n = 55 of 654, 8%)

The chart uses each product's longest base warranty term. Money-back and return periods, perks of a plan, subscription or club, rental- or commercial-only terms and terms for one component (such as a motor, belt, battery or emissions parts) are not counted as a base term. 19 products still name more than one base term, for example where two maker documents differ.

Category spotlights (small samples)

These are single categories with fewer than 20 products each, so treat them as a look at the models we cover, not a rule for the whole category. Each row links our guide and, where the maker hosts the document, the source.

Generator manuals and pages that give a minimum distance

17 of 35 generator guides have a minimum distance recorded from the maker's manual or page. Seven give a distance from the house, doors, windows or other openings, and those figures run from 18 inches to 20 feet; the shortest figures are for home standby units, measured from the structure. Nine give a distance from combustibles, all 5 feet. Small sample: read it as the models we cover, not a rule for the whole category.

Pellet grill minimum clearance to combustibles

6 of 12 pellet grill guides record a minimum clearance to combustibles. The figures run from 18 inches to 3 feet, and one adds a larger figure for combustibles overhead. Small sample: read it as the models we cover, not a rule for the whole category.

Space heater distance from combustibles

4 of 9 space heater guides record how far to keep combustibles away, and all four say 3 feet, measured at least from the front of the heater. Small sample: read it as the models we cover, not a rule for the whole category.

Portable power station charging temperature ranges

12 of 18 portable power station guides record a charging temperature range. For seven of them the range starts at 32 °F or warmer; the lowest starting point recorded is -4 °F. Small sample: read it as the models we cover, not a rule for the whole category.

Runtime figures tied to a stated load

9 products tie a headline runtime to a stated load. Eight are generators that give runtime at a share of rated load such as 25% or 50%; the other one bases the figure on running with no load. Small sample: read it as the models we cover, not a rule for the whole category.

Counts by category

How many guides in each category have each kind of fine print recorded. Open a category to see its guides.

A zero means our notes did not record it, not that the maker's documents are silent. The median longest warranty is shown when at least 3 guides in the category have a term recorded.

Every kind of fine print we counted

Method and limits

What we read

The source is our own research notes for the 654 product guides live when the study was run. For each product, researchers read the maker documents they could find (product pages, owner's manuals, spec sheets and warranty terms) and wrote down the figures and short quotes they used, with the address of each document. The dated note files run from 19 September 2026 to 24 September 2026. All 654 guides have a note section we could match to the product. Of the 1479 data points, 1108 come from product-specific documents on the maker's or brand owner's own sites, 96 from the maker's brand-wide warranty or policy pages (which apply to the product but are not written for one model), 18 from maker documents hosted by the retailer that distributes the brand and 257 from the maker's manual attached to the Amazon listing. Amazon listing text is never counted.

How a statement gets in

A script (tools/fine_print_study.py in our repository) reads the notes, splits them into clauses and looks for 24 kinds of fine print, such as warranty terms, who the warranty covers, what voids it, clearance distances, maintenance intervals and temperature ranges. A clause counts only when the note line carries the source URL, or sits in a bullet list under a line that does. Lines about the retail listing, lists of conflicts between sources and notes on pages that were not read are skipped. Notes for products we withheld or retired are skipped. The same statement from the same URL is counted once.

How we count

Every figure counts distinct products. Shares use the 654 guides with notes as the base. Kinds of fine print found for fewer than 20 products are shown as small samples and kept out of the headline findings. A product can appear under several kinds, and under more than one value when its documents give more than one (for example two maker documents that give different warranty terms, or a clearance to walls and a clearance to combustibles).

Hand check

The study's author drew a fixed random sample of 60 rows and compared each with the note line it came from. Seven of those rows are no longer produced (products withdrawn from the catalog, or rows changed by the review fixes described next), so the counts are for the remaining 53: 53 were right as recorded, 0 borderline and 0 wrong. This is a self-check. An independent reviewer then re-checked 72 other rows across every kind of fine print and every category: 65 were correct, 5 borderline and 2 wrong. Both wrong rows (a plan-perk lifetime warranty, a rating rule read as maker-only parts), two of the borderline classes it named (payer not named for prepaid returns, a manual figure tied to the page that links it) and the other warranty and charging misreads it listed (money-back periods, club perks, rental-only and single-component terms, a pre-charge hold temperature, one quote with disagreeing °F and °C) were fixed in the extraction rules before this snapshot. In a second independent pass the reviewer checked 20 fresh rows: 17 were correct, 2 borderline and 1 wrong. The wrong row (an extension-cord ban read as a rating rule) was fixed in the extraction rules, and one borderline class (a maker manual hosted by the retailer that distributes the brand) is now labelled as such; the other borderline row (a warranty that also covers a gift recipient, recorded as original purchaser only) is unchanged.

Limits

• This is a sample of the models we cover, not a census of the market. Brands and categories we cover more heavily count more.
• The counts are floors. The notes record what each guide needed, so a missing rule is often a rule nobody wrote down.
• Pattern matching misses some statements and can misread others; the hand check above gives a sense of the error rate.
• Maker documents change. The CSV gives the URL and our note line for every data point, so each one can be checked against the current document.
• This is a summary of what documents say, not legal advice and not a reading of any warranty's full terms. For a real claim, read the maker's current terms for your exact model.

Download the data

fine-print-study.csv has one row per product, kind of fine print, value and source (1479 rows). Columns:

• asin, product, category: the product and its category on this site.
• fact_type, value, value_num, value_unit: what the document says, with a number where there is one (months, inches, hours or °F).
• source_url, source_kind: the maker document the statement came from.
• evidence_file, evidence_line, evidence_excerpt: where it sits in our research notes, and the words there.
• product_page: our guide for the product.

How to cite

If you use a figure from this study, please name Plain Buy Guides and link this page or the CSV:

Plain Buy Guides. “Fine print study: warranty and manual rules in 654 products.” 24 September 2026. https://plainbuyguides.com/fine-print-study. Dataset: https://plainbuyguides.com/fine-print-study.csv.

Licence: our compilation (the selection, classification and counts in this study, the CSV's structure and values, and the text and figures on this page) is published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt it with credit to Plain Buy Guides and a link to this page. The short excerpts quoted from maker documents (the evidence_excerpt column and the “What our note says” cells) are not covered by this licence and remain the copyright of their makers; brand and product names belong to their owners.

Questions or a correction? See About and disclosures for how to reach us. We fix confirmed errors and note the change on this page.