19 Home Mistakes You Can’t Afford to Make

Updated: Jan. 29, 2024

Save time, money and frustration by avoiding these home care and repair mistakes that you won't realize you've made until it's too late.

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Furnace filter
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Never Changing the Furnace Filter

Clogged air filters are usually to blame when a furnace stops working. Dirty air filters are also hard on blower motors and heat exchangers, so it’s a good idea to replace your air filter before there’s a problem.

It can be hard to remember to check it regularly, so that’s where an air filter gauge can help. It eliminates guesswork by measuring airflow and telling you exactly when it’s time to change your air filter. Plus: You really need to know these 21 air conditioner maintenance and home cooling tips.

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removing load bearing wall
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Knocking Down a Load-Bearing Wall

In older frame houses, homeowners are often tempted to remove walls and create a more open floor plan. The danger is, if the wall that’s removed is a load-bearing wall, the second floor might end up falling onto the first! If you’re not sure, have an inspector determine if it’s safe to remove the wall. And learn much more about wall removal and replacement.

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FH10SEP_511_54_049 garage door opener
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Forgetting to Read the Installation Manual

After installing a garage door opener and spending hours trying to figure out why it wouldn’t work, one frustrated DIYer learned a tough lesson. His neighbor came over, picked up the manual that came with the opener and called the manufacturer’s help line. After one simple question, the customer service representative solved the problem. He asked if the cover was on the opener because it won’t work until the cover is on. That was the problem.

The lesson? No matter what you’re installing, read the manual, keep the manual and use the customer service helpline if you have any problems. For additional advice about installing garage door openers, check out these pro tips.

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programmable thermostat Setting thermostat
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Never Checking the Thermostat

Did you know you can save money on your energy bills by monitoring and setting your thermostat? Simply reset your thermostat at night and when you are away from home. According to the U.S. Department of Energy, “You can save as much as 10 percent per year on heating and cooling by simply turning your thermostat back seven to 10 degrees for eight hours a day from its normal setting.”

Thermostat still not working? Here’s how to adjust it.

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Never Checking the Power on the Furnace

Make sure the power is on! The power switch for your furnace looks like a regular light switch and can get bumped and turned off accidentally. If the switch is off, just flip it back on.

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Starting Up the AC Without Doing This:

On the first hot day in spring or summer, what will you do if you turn on the air conditioner and it doesn’t work? Don’t make the mistake of calling a service technician before you check this common oversight.

Move the thermostat mode switch from ‘Cooling’ to ‘Off’ and move the fan switch from ‘Auto’ to ‘On.’ Let the blower run for at least 30 minutes or until there’s good airflow at the registers. Then turn the AC back on to test it. If it keeps working, you’ve fixed the problem yourself! For more DIY AC repair help, check out our complete guide.

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Painting Glossy Paint on a Bad Surface

You may love the look of high-gloss paint, but if you apply a glossy paint to surfaces that aren’t perfect, the paint will accentuate the problems. Light reflecting off the shiny paint will highlight every defect. So if you want to paint with a semigloss or gloss sheen, make sure the surface you’re painting is carefully prepared and perfectly smooth. Here’s how to prepare wood trim for painting.

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Painting the Ceiling Without Wearing a Hat

When you roll paint on a ceiling, little splatters of paint go everywhere and many will land on your head. It may not be the biggest deal but it is a pain to clean up. Wear an old hat and expect it to be covered with paint specks when the job is done. Take it from a pro, here’s how to successfully paint a ceiling.

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Making Rookie Mistakes

Two common first-time painting mistakes:

  1. Leaving the lid off of the paint can. The most obvious problem with this bad habit is that someone is bound to step on the lid and track paint all over. But there are other reasons to put the lid back on immediately. It’ll keep your paint clean and prevent dried-out paint crud from forming in the can or on the lid. Plus, you’re less likely to get the lids from two similar colors mixed up, which can cause hassles later. Follow these expert tips for storing paint cans.
  2.  Forgetting to lock out pets. Here’s what can happen — you step out of the room you’re painting and pretty soon your dog is in there sniffing around. He grabs the paint brush handle in his mouth and carries it, dripping, across the house to give it back to you, leaving painted paw prints in his path. Avoid all pet-related painting problems by keeping your pets locked away from the project at all times.
10 / 19
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Fertilizing at the Wrong Time of Year

If you fertilize your lawn only when you think it needs it — like when you have time or when fertilizer is on sale — you may be wasting time and money. Fertilizers need to be applied at certain times during the growing season. For more on when and how to fertilize your lawn, check out these pro tips.

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Never Resetting Your Ice Maker

When you clean your refrigerator and freezer before leaving for a period of time, be sure to replace the ice tray. If you don’t, the ice maker doesn’t get the signal that the tray is full, so it keeps making ice until the freezer is full! The next time you open the door, watch out! Also, some ice makers have a lever you can lift to make sure no ice is made while you’re away.

If your ice maker needs replacing, you can do it yourself. Here’s how.

12 / 19
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Never Cleaning Your Dryer Lint Screen

If your gas clothes dryer isn’t getting your clothes dry, the culprit is often a lint-clogged vent. Use a vacuum and/or a brush to clean out the lint and the dryer should work fine, unless you accidentally shut off the gas valve.

Service technicians see this all the time. Someone gets in there and cleans out all the lint, pushes the gas valve closed without knowing it and ends up calling a technician. All they have to do is reach in and turn on the valve, and charge you for the service call.

13 / 19
programmable thermostat
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Never Changing the Thermostat Batteries

If your home is still chilly after turning up the thermostat and checking to make sure the furnace is on, try changing the thermostat batteries before you call a technician. Programmable thermostats have batteries and it’s easy to forget to replace them regularly.

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smart ceiling fan
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Installing an Improperly Sized Fan

If you have a ceiling fan that needs replacing, it’s tempting to go up a size or two to move more air. That’s what one DIYer did. Everyone loved the result until the first time someone opened the cupboard doors while the fan was on. A series of loud bangs later, they realized the longer fan blades were whacking the edges of the cupboard door!

Instead of taking down the new fan, this family put a rubber band on the cupboard door handles to remind everyone not to open them when the fan is on. This ceiling fan installation guide has everything you need to know, even if you have an angled ceiling.

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Forgetting Crucial Installation Steps

Installing a new garbage disposal is a perfect DIY project. You don’t need lots of tools, you get the satisfaction of solving the problem without hiring a pro, plus you save a bundle of cash.

But there’s one important thing that may not be mentioned in the installation instructions: You must remove the factory plug from the drain line that runs to the dishwasher. If you don’t remove this plug, your dishwasher can’t drain. For additional ways to avoid leaks and mistakes when installing a garbage disposal, check out this guide.

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Cutting Off the Wrong End

This is a classic mistake. You have a door that needs to be trimmed to clear new carpet or some other flooring change. You remove the door, put it on sawhorses, measure carefully and make the cut. When you go to reinstall the door you realize you’ve cut off the top of the door instead of the bottom.

Always put a mark on the bottom of the door before you remove it and look for that mark before you start to cut. If you want to cut off the bottom of a door without splintering, use this guide.

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Not Measuring Carefully

Replacing a toilet isn’t difficult and it’s a standard part of any bathroom upgrade. But a word of warning, especially for small bathrooms: Carefully measure the amount of space between the toilet and the door as it closes.

More than one DIYer has installed a new toilet, with the door open, and found out later that the door would no longer close because the new toilet protruded farther than the original. Once you’re sure the toilet is the right size, follow this guide to a trouble-free, leak-free installation.

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Not Taking Everything Into Consideration

When you remodel a bathroom, carefully measure to make sure your new lights and medicine cabinet work well together. Say you replace sconce lights with an overhead fixture. If you install the light too low, you may not be able to open the medicine cabinet door.

Are you thinking about remodeling a bathroom? Check out all of these clever ideas and step-by-step how-to articles.

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Not Calling Before Digging

Did you know there’s a nationwide number you can call before you dig? Call 811 to have your underground utility lines marked — for free. We recommend calling before starting any project that requires digging, even small projects like planting shrubs.

Hitting an underground utility line with your shovel can knock out power to your house or neighborhood, and it can cause serious bodily harm — even death — not to mention a rather large bill from the utility company. This is the best way to dig a hole.

When you call 811 from anywhere in the country, your call is routed to affected utility companies. They send out a professional locator to mark the underground lines, usually within a few days. For more information, visit call811.com. The other one-call referral system number we’ve featured, (888) 258-0808, can still be used to have your underground utilities marked.