I see them range from $100 to $800 and wonder what I need.
I have a small apartment with wall-to-wall. I’m not concerned at all about how long the job takes, just whether the carpet looks clean.
I would guess that those with on-board heaters are best, but if a cheap one works I could live with refilling it a few times to keep the water hot.
We recently got all hardwood floors but kept the carpeting on the stairs.
So all of the dust from the hardwood floors gathered on bare feet, shoes, socks, whatever footwear, and was transfered to the carpet.
We bought an inexpensive carpet shampooer, we went to home depot and got the big carpet shampooer, we went to Walmart, K-Mart, Lowes, Home Depot (again) and an industrial supply shop and we bought every chemical treatment on the market to get those steps cleaned. We then tried home remedies - vinegar, or ammonia, or simple soap and water.
Finally we found a way to keep the stairs clean!
We ripped out the damned carpet and put in tile.
Ouch!
I have a Bissell unit which connects to the hot water faucet. It sprays a diluted detergent/water solution onto the carpet and sucks it back up along with soil. I’ve used it for many years, and it performs very well.
Just for balance, we’ve got a Hoover Steamvac “V2” model that goes for about $250. We’ve been very happy with it and use it surprisingly often. Oddly, Bissell shampoo seems to work better for us than the Hoover shampoo. It’s got an onboard tank for hot water from the tap. Ours doesn’t heat the water, though. Our favorite characteristic of is is that it leaves the carpet nearly dry.
If you’re just renting the place, why not rent a carpet cleaner from the grocery store? I wouldn’t recommend renting if you owned your home, but as these things are usually a bit larger than a typical upright vacuum, they do eat a lot of storage space.
Looking at the buyer reviews of the one we have at Amazon, it almost looks like we were lucky and got a good one. Home carpet shampooers as a category seem to be about the most troublesome and likely to fail thing you’d ever buy. From experience, I can say that’s true - we used to have a hand-held unit that just didn’t have the guts, and a Bissell upright cleaner that lasted about a year and a half before it started leaking.
I have a cheap (<$100) Bissel and it works well. It even cleans up grease stains from my bicycles if I spray the stains first.