Having carpets periodically cleaned makes them last longer and look better, and it improves your home’s air quality.

The company you hire will impact how well the job gets done, whether difficult stains are removed, how good your carpets and rugs look afterward, and how long they stay that way. With the least-competent companies you risk permanent damage from overwetting, improper or poorly mixed chemicals, bad brushing, and other shoddy practices.

Start by consulting our Ratings Tables, which report results from our surveys of local consumers, complaint counts, the areas companies serve, and how operations compare on price.

Feedback from Customers

Our Ratings Tables report the results of our surveys of local consumers. We primarily surveyed Consumers’ Checkbook subscribers, but also invited a sample of other area homeowners to participate. We asked them to rate carpet- and rug-cleaning companies they had used “inferior,” “adequate,” or “superior” for several questions, including: “neatness,” “doing work properly on the first try,” “promptness,” “advice on service options and costs,” and “overall quality.” For companies that received 10 or more ratings, our Ratings Tables report the percent of surveyed customers who rated each company “superior” (as opposed to “inferior” or “adequate”) on each question. Click here for more information on our customer survey and other research methods.

As you can see, many professional cleaning services consistently perform great work. The highest-rated companies were rated “superior” by more than 90 percent of their surveyed customers on most of our questions. But some other companies received low scores.

Complaint Records

Our Ratings Tables also report counts of complaints we gathered from the Consumer Protection Division of the Washington Office of the Attorney General for a recent two-year period and complaint rates relative to the volume of work companies do. Click here for more information on reported complaint counts and rates.

Guarantees

Most carpet-cleaning outfits provide guarantees, but their promises vary. Give companies credit if they talk candidly about their limitations before they begin the work—some stains are extremely difficult or even impossible to remove once they’ve set, and companies may not know whether they can zap them until they try.

Some companies may have you sign forms in advance explicitly excluding a wide range of trouble spots from their responsibility. Look for another outfit that does promise to take care of the problems that concern you.

If your carpet is still under its manufacturer’s warranty, also ask the company if its services keep the warranty in effect. Carpet manufacturers’ warranties are notably murky about coverage for “wear” and “appearance,” and many include a clause declaring that, for certain sections of the warranty to remain in effect, the buyer must prove the carpet was “professionally maintained.” This typically means the carpet must be professionally cleaned once every 12 to 18 months via a hot-water-extraction method. That’s a very expensive requirement, but if you care about warranty coverage, show the policy to the cleaning service and have it assure you that its services meet the requirements.

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Do They Use Effective Cleaning Methods?

Some cleaning methods work better than others, depending on the condition of your carpet or rugs. Most Oriental rugs should be cleaned at a company’s plant using an immersion method—click here for details and best practices for rug-cleaning jobs. For lightly soiled carpet, any method performed properly is acceptable, but in most cases you’re best off with a company that offers hot-water extraction with truck-mounted equipment.

Here’s a rundown of the pros and cons of various methods:

Hot Water Extraction

Also called “steam cleaning,” this technique sprays hot water (or water plus a mild detergent) into carpet pile and then immediately vacuums it—and grime—out. Performed properly, hot water extraction can clean even filthy carpets.

Hot water extraction is done with portable units or truck-mounted equipment; the latter generally works better on really dirty carpets—its higher temperatures and pressure penetrate deeply into carpet pile.

The extraction machines work better if the carpet is sprayed with conditioner and lightly agitated with brushes before cleaning. The conditioner acts as a degreasing agent, which assists in removing dirt and grime; it also lubricates the carpet so the hot-water-extraction wand doesn’t distort the pile.

For years, companies affiliated with the Chem-Dry brand used a modified bonnet method (see next page), but most now usually use its hot-water-extraction method, which mixes in a carbonated solution that, in theory, requires less moisture to be effective.

Shampoo

Carpet shampoos are a lot like laundry detergent. Some also contain chemicals to reduce odor, retard soiling, brighten colors, and speed drying. Cleaners use a rotary brush that releases shampoo onto the carpet, converts it into foam, and works it in. When the shampoo dries, it leaves dry particles that can be vacuumed up.

However, those loosened dirt particles might not get removed and may simply work deeper into the pile. Too much (or lousy) detergent may cause a sticky buildup on carpet fibers. And repeated cleanings without proper extraction can compound this problem, accelerating re-soiling.

Combined Shampoo and Hot Water Extraction

High-powered truck-mounted hot-water-extraction equipment usually cleans even heavily soiled carpet—especially if it is treated with conditioner. But for really grimy jobs, some companies recommend a two-step shampoo-then-hot-water-extraction process.

Foams

Foams are really just a form of shampoo. The foam is generated by machines that also agitate it on the carpet with brushes. You can use aerosol cans of foam at home, applying it in a thin layer and rubbing it in with a damp sponge. When it dries, simply vacuum up the residue. The main advantage to do-it-yourself users is that foam contains very little moisture, so you’re unlikely to damage carpet by getting it too wet. But this also means that not much soil is removed, so you’re cleaning only the carpet’s surface. Plus, some foams are difficult to rinse out and may interfere with later cleaning attempts.

Bonnet

Originally meant for commercial carpeting, bonnet cleaning uses a round absorbent pad, or bonnet, attached to the bottom of a rotary floor machine. Detergent is sprayed onto the carpet; then the pad is rotated over the surface, removing soil that adheres to it. When one side of the pad is soiled, it is reversed; when both sides are soiled, the pad is rinsed.

The bonnet method shares many of the same limitations as shampooing—many loosened dirt particles are never removed and simply work their way deeper into the carpet pile. The incorrect amount of detergent may produce a sticky buildup. And since companies using this method rarely employ a rinse process, repeated cleanings can overload the carpet with residues that may accelerate re-soiling.

Absorbent Dry Compounds

Dry powdery compounds containing detergents or solvents can be sprinkled on the carpet, worked into the pile by machine, then removed by a vacuum cleaner. The detergent or solvent dissolves the oily film on carpet fibers, freeing the soil to be vacuumed out along with the powder after about half an hour. Although usually less effective than other methods, dry compound cleaning has special applications.