Your vacuum cleaner died the other day and news from the repair shop is not good. Looks as if it's time to buy a new one.

Your vacuum cleaner died the other day and news from the repair shop is not good. Looks as if it's time to buy a new one.

Should you get an upright or canister model? Bag or bag-less? How often does it need to be serviced? How much should you spend? Vacuums come in a wide price range, anywhere from $39 to over $1,000, with most good ones $300 to $500.

"You want to pick a vacuum that excels at your toughest need," suggests John Matlock, manager of Ernie's Vacuum and Sewing Center in Medford.

So ask yourself: Is your home primarily carpeted, or do you have a lot of vinyl and hardwood floors? Do you have stairs? Do you have pets that shed?

If you have a lot of dog hair in your home but you bought a portable "jack-of-all-trades" kind of vacuum, it may do a mediocre job of removing dog hair, says Matlock. "You'd be better off with a unit that performs well on your toughest, dirtiest rug." But that unit might be heavy, and if you have stairs you don't want a machine that would be too hard to lift.

Uprights are the choice for vacuuming carpet. "When you see a janitor vacuuming carpet in a public building you always see the person using an upright," says Matlock.

But if you have a hard floor as in hardwood or vinyl, a canister unit works best, says Jack Hawkins, salesman at Green's Sewing and Vacuum Distributors of Medford.

Canister units come in two sizes. If you're going to use it just to vacuum out the car, get the smaller one, says Matlock. But if you also want it to do a good job on flooring, get what's called a "team" unit, so-called because it has two motors.

Not having to buy and change bags may have appeal, but "bag-less cleaners are dirty and also messy to empty, which is not helpful if you have allergies," says Hawkins. "And they use expensive filters instead of bags." He doesn't recommend them, stating flatly, "There is not a good quality bag-less model out there."

Bags do cost money, but when you replace the dirty bag with a fresh one you get good airflow and less contamination, says Matlock.

And, as Hawkins points out, "Airflow is very important, more important than suction. It is airflow that removes the dirt. The more airflow you have, the deeper into the carpet you can clean."

Most upright models have plastic or wood bottoms where the rollers and brushes are located. Find one with steel if you can. That's because with steel rollers you can change the brush bristles, says Matlock. With plastic or wood, you can't. "Brushes are a large part of how a vacuum works," he says. "If the brushes get worn, the machine will stop picking up dirt. Suction alone doesn't do it."

If you have pets that shed, Hawkins suggests looking for a unit that has an aggressive brush capability. "Not many machines do a good job picking up pet hair, but an aggressive brush will help," he says. It can pull out pet hair and also do a better job of grooming the carpet.

Some other questions to ask the salesperson could include: Do you take trade-ins? Does the purchase include free annual servicing for several years?

Finally, don't overbuy, says Matlock. Get a machine that does what you need, not a more expensive one that performs functions you'd rarely use.