How we review

Each comparison gives every product a score in a few named areas and an overall grade. Here is what goes into them.

What we look at

We start from information anyone can check: the maker's published specifications and instructions, the seller's price, return, money-back and warranty terms, and public buyer reviews. We read buyer reviews for patterns that show up after weeks of use (faults, noise, how a product holds up), not for star counts alone.

The scores

Each category uses areas that matter for that kind of product. For heaters these are heating speed, room coverage, controls, safety features, and money-back terms. Every area gets a score out of ten; the overall grade is the average, shown as a number and as a letter.

9.5 and above is A+. 9.0 to 9.4 is A. 8.5 to 8.9 is B+. 8.0 to 8.4 is B. 7.5 to 7.9 is C+. 7.0 to 7.4 is C. We do not usually include products below 7.0.

What we do not do

• We do not run a laboratory or test products ourselves. We compare what is published and what buyers report.
• We do not accept payment to change a score. Commissions can influence which products we cover and where they appear on a page, as our Advertising Disclosure explains.
• We do not make claims a maker does not make, and we do not invent ratings, user counts or awards.

Corrections

Prices, offers and return terms change. If something on a page is out of date, email support@shopperbriefing.com and we will check it.