Microwave Review

Evaluating microwave performance and reliability

Today's microwaves come in two main varieties -- countertop or over-the-range models. Countertop microwaves are available in a variety of sizes, from compact 0.8-cubic-foot units appropriate for apartments and dorm rooms, to more spacious full-size 2.2-cubic-foot models that can accommodate 9-by-13-inch baking pans. These microwaves just plug into a regular outlet. Some microwaves can be installed under a cabinet, but consumers may need to buy an optional trim kit ($100 to $150, depending on the brand) for extra venting. Over-the-range microwaves typically cost $200 to $500. Full-size countertop models run in the $100 to $300 range, while compact microwaves are even cheaper, often costing less than $100, but they also possess weaker cooking power (around 800 watts). Full-size microwaves have more power -- around 1,100 to 1,300 watts, which shortens cooking time.

As their name suggests, over-the-range microwaves are meant to be mounted over a range, so they include lights on the bottom and extra vents to move heat away from the stove. Most models are designed to fit into a 30-inch-wide space -- the common width of a range -- and capacities are similar, around 1.8 cubic feet for most models. Most over-the-range microwaves also require professional installation, particularly if consumers don't already have a dedicated electrical outlet and a vent to the outside in the space where the microwave will be installed. Both countertop and over-the-range microwaves typically come with a one-year warranty, although many brands provide lengthier coverage for the magnetron, a tube that produces microwave energy.

There have also been some new developments in microwave technology in the last few years that have resulted in more innovative product features: the integration of cooking sensors, convection ovens and inverter technologies. Cooking sensors measure the humidity in a microwave and then automatically adjust cooking times to prevent overcooking. Many find this feature appealing, and it works well on most microwaves, according to expert and user reviews.

Inverter technology is another new feature. Unlike standard microwaves, which cycle between periods of 100 percent power and no heat, a microwave that uses inverter technology has the ability to cook continuously at half power, which results in more even cooking. While users say this feature does work, we saw more reliability complaints for microwaves with inverter technology than those without it. In particular, many owners report that these microwaves have a tendency to fail within a few years (and sometimes even less than that) when the heating element breaks down -- the microwave either looks like it's working but is not heating, or it turns off after several seconds.

Another popular product feature is a convection-oven mode. With convection technology, ovens use traditional microwave heating and a small fan to circulate heat throughout the oven, a process that promotes more even cooking and surface browning -- a weak spot for microwaves. This enables the oven to produce a roast chicken with crispy, browned skin or fries that are golden and crunchy. However, a convection feature can add significantly to the price of a microwave, so if you mainly want to reheat and defrost foods, a standard microwave will be more cost effective. Top-rated microwave ovens usually cost about $100 less than comparably sized microwaves with convection.

Overall, ConsumerReports.org offers the most credible microwave reviews and testing. In its most recent evaluation, the organization tests nearly 70 countertop and over-the-range microwaves, rating each on heating evenness, noise, auto-defrost and ease of use. Good Housekeeping magazine editors also test 17 microwaves and recommend several models, but their testing process is not explained, and the microwaves are not individually rated. To supplement the professional reviews we found, we checked expert picks against reviews at online retailers like ABT.com, Sears.com and BestBuy.com, in addition to user-review sites like Epinions.com and Buzzillions.com. User feedback is helpful for gauging long-term reliability.

Few microwaves were recalled last year, but the Samsung SMH9151 -- a top-rated over-the-range model in one independent test -- was recalled in November 2009. According to the Consumer Product Safety Commission, the microwave poses a potential shock hazard. The recall involves microwaves sold between January and June of 2009; affected consumers should contact Samsung for a free repair.