Carpet deep cleaners are often erroneously called steam cleaners, even by the manufacturers. They do not use steam. Instead they use a mixture of hot water and detergent. This mixture is squirted onto the carpet. The carpet is brushed vigorously and the resulting mixture of water, detergent and dirt is sucked back up by the vacuum component of the cleaner.
Upright or Canister?
The first decision to make is whether you want an upright model or a canister model. Just like their vacuum cleaner counterparts, a canister has a cylindrical unit with an extendible hose, while an upright model has wheels and a handle and is pushed over the carpet. Each has its advantages.
Advantages of Uprights
* Easier to store.
* More attachments.
* Easy to move, since they always have wheels.
Advantages of Canisters/Portables
* Easy to use on stairs and upholstery.
* Some are good for spot cleaning.
* Some more expensive models get very good reviews.
As with any appliance, breakages, leaks and other malfunctions may happen. If cleaning your carpets is a priority in your home then the investment is one worth making. They can be handy if you have pets (even the best trained may still occasionally stain your carpet) or if your kids are prone to making a mess.
As Captain Kirk liked to say, there are always alternatives. There are many rental services from which you can lease a carpet cleaning appliance for a day. Doing this frequently may add up but for the occasional cleaning it is probably worthwhile. You won't have to worry about where to store another large appliance. Another option is to hire a professional cleaning service to clean your carpets. It's expensive, but the results are better than you'll get by yourself.