You flip the switch and the heat goes on. You make your mortgage payments and your lender is not threatening you. So all's right with the house. Or not. The furnace needs professional maintenance to run efficiently and the mortgage isn't the only payment you need to be on top of. Even in this market, when real estate prices are falling, a home is likely to be the biggest monetary investment their owners make. But homes need TLC so they don't crumble physically or financially. "Fall is the Goldilocks season for home improvement. It's not too hot, it's not too cold. It's just right," said Tom Kraeutler, co-author of My Home, My Money Pit, adding that now is a good time to evaluate your home's needs and what you should do to protect your investment. Here are 10 musts: 1 Check your home's major systems; have them professionally serviced.: Can't get on the roof? Check it by lying on the ground where the angle of the roof would meet the dirt for the best view of problem shingles, Kraeutler said. Then tap outside wood with a screwdriver to detect rot, examine caulk and make sure the foundation has no horizontal cracks more than 1/8 -inch-wide. Have the heating and air conditioning inspected and serviced; have carbon monoxide levels in the home measured and make sure some critter hasn't built a condo that blocks your chimney. Open all faucets at once, make sure everything drains, and keep water running while you look for leaks in plumbing. 2 Be smart about renovations.: Go with the statistics, your budget, your lifestyle and the fit for your neighborhood, advises Ilene S. Kessler, a past president of the Maryland Association of Realtors and an agent with Re/Max Advantage in Columbia. Modernized kitchens make your life easier and offer good resale value, she said. "You've got to have a good design. The countertop won't matter as much if you have a good design," she said. "It's got to be functional and it's got to be workable." Consider renovating bathrooms and making improvements to get the best use of closet space. Improve but don't overimprove. You're unlikely to realize good resale value from that. "Understand what people in your neighborhood have," Kessler said. 3 Practice fire prevention and safety.: Test smoke detectors monthly and install new batteries twice a year, when you change your clocks for daylight saving time (which ended this morning). Never disable a smoke detector - if it goes off while you're cooking, then it's doing its job. William Smith, deputy chief of the Howard County Fire Marshals Office, also recommends that homeowners place ABC-type fire extinguishers in the kitchen, basement and garage. But first, homeowners should take a class to learn how to use the extinguisher effectively. "We don't want them to use it for the first time when they have a fire," says Smith. For new homes, Smith says installing sprinklers is a good option. 4 Keep current on home maintenance.: Peeling caulk and rooflines sprouting 2-foot-tall saplings do not send a message that your house is well-kept. "These are tough times for a lot of people, and they can't do upgrades," said Cara Shea Kohler, an agent with Coldwell Banker Residential Brokerage's Roland Park-Cross Keys office. But clean, tidy and well-maintained says that you're on top of things. Clear gutters and downspouts; paint where it's needed to protect the surfaces; and clean your windows. Kohler said a lot of basic home maintenance is more of a pain in the neck than an expense, but it needs to be done, especially if you are thinking about selling. A broken window sash or chipped paint on a door send a message that "if they can't even do that, then what's going on with the furnace," she said. 5 Keep home insurance up to date and be familiar with your policies.: "I know people don't read these. They just put them in a file," said Lisa Fuller, owner-principal of Fuller & Associates Insurance in Churchville. But that can lead to inadequate protection and paying for unneeded coverage. "Have your insurance agent reevaluate what the cost to rebuild your house would be," Fuller said. What you want, she said, is 100 percent guaranteed replacement cost. Tell your agent about upgrades, additions and renovations. Flood insurance is separate. If you have not listed everything you have at home, or photographed your house, or done a room-by-room video, do it, and store it, along with important papers, elsewhere. 6 Use landscaping.: Planting trees and shrubs can protect your home and save you money, says Diana Coleman, coordinator of the Growing Home Campaign, a program that encourages tree planting in partnership with local nurseries and retailers. Trees provide shade and windbreaks, reducing energy costs for homeowners, Coleman says. They also slow stormwater runoff, protect soil, clean the air and beautify neighborhoods. As part of the program, homeowners in the city and in Baltimore and Harford counties can receive a $10 coupon toward the purchase of a tree. "Fall is a very good time to plant trees," says Coleman, who manages the program through Baltimore County's Department of Environmental Protection and Resource Management. "The ground is still warm ... so if you get a tree in the ground, it gets settled in and as soon as spring breaks, it's ready to go, ready to grow." 7 Be credit smart and mortgage smart.: Know the ins and outs of your credit score and your mortgage. James F. Ludwick, president and founder of Main Street Financial Planning in Odenton and Washington, tells his clients to read You're Nothing But a Number, by John Ulzheimer, for a primer on credit scores, debunking credit myths and learning credit facts. Other advice: Check your credit reports with the three companies, Experian, Equifax, and TransUnion, to ensure each one's information on you is correct. You can order free credit reports through annualcreditreport.com. "Pay on time, not racking up too much debt in relation to your limit. Consistently being above half of the limit is a bad thing," Ludwick said. Unless you're sure your lender is escrowing your taxes and insurance - that means one-twelfth of taxes and insurance are added every month to your mortgage payment - double-check. "Some lenders insist on it, but most of them will give you a choice," he said. "By escrowing it, you are forgoing $5 or $10 in interest, but that is your cost of making sure it goes in on time and that you have shifted that responsibility to the lender," he said. 8 Get involved with your homeowners association.: You don't want to be surprised by the new 10-story building that replaces the wooded view from your backyard. But even more importantly, says Jeanne N. Ketley, president of the Maryland Homeowners' Association, you don't want to suddenly find out that your HOA is broke, either because of mismanagement or nefarious intent. "Anyone living in a condominium or a co-op needs to be aware of the financial status of that organization," says Ketley, who represents a group that provides information for HOAs. "If you don't hear something, you figure that everything is OK. But that might not be the case." Ketley recommends homeowners go to board meetings and/or get copies of the minutes and monthly financial statements. "Sometimes they are on an intranet or someplace that everyone can see," she says, but even if they are not, make a special effort to go to the office or a neighbor's house to get the records. "If they don't want you to readily have that information," Ketley says, "then something is wrong." 9 Be careful in using home equity credit.: "It's a good backup for emergencies and maybe also for a college fund," said Christopher Brown, president of Ivy League Financial Advisors in Rockville. He advises homeowners to establish the credit line while they're in good financial standing in case they need it. Traditionally, because people should have three to six months of living expenses available in case of illness or job loss, the home equity line has been an alternative way to accomplish that. To buy a car? No. To take a vacation? No. To build your dream kitchen? No. "Don't use it for anything that expands what your current consumption is," Brown said. If you're thinking of moving, forget this piggy bank. 10 Be energy smart.: You'll save money and protect your home value because buyers don't want mega-bills any more than you do. Insulate, starting with batting in the attic: "If you don't have 16 inches of fiberglass, you don't have enough," Kraeutler said. Window replacements are another energy-saver with high resale value, but they are a big investment. Want to start small? Renovating, replacing, repairing, painting? Look for green products. Start with Energy Star appliances, fluorescent lights/fixtures, a programmable thermostat and very low VOC (volatile organice compound) paints.