1. Peeling Exterior Paint

Cause: Moisture is probably getting underneath the paint, perhaps from a leaking gutter overhead or from a steamy bathroom on the other side of the wall.

Cure: If you catch the problem right away, you might just need to address the moisture issue and then scrape off the loose paint, prime bare spots, and repaint that wall, for a total of a few hundred to a couple thousand dollars. Delay too long and the siding might rot. Patching and repainting the whole house could cost $10,000. 

To prevent a chronically steamy bathroom, install a new ventilation fan with a humidity-sensing switch that automatically exhausts moisture-laden air. Cost is about $250.

2. Flickering Lights

Cause: If only a single bulb flickers, it might be loose in its socket or in need of replacement. If lights always dim when the refrigerator or other appliance turns on, the circuit might be overloaded. If groups of lights flicker, connections at the electrical panel or elsewhere might be loose, causing power to arc — or jump — over the gaps. Arcing is a serious problem; it starts fires.

Cure: Anyone can tighten a bulb. Handy homeowners can shut off circuits and tighten loose connections within switch boxes. If you’re not comfortable doing that, or if you suspect an overloaded circuit or loose connection at the panel box, call in a licensed electrician. You’ll pay a bit for a new circuit and more for a new electrical panel — way less than what you’d spend to recover from a fire.

3. Rustling in a Wall

Cause: Sure, termites usually signal their presence by building pencil-thick mud tubes up from the ground or by swarming from pinholes in floors or walls. But did you know it’s also possible to detect them by sound? Tap on a wall and then press an ear against it. If you hear a rustling sound, it could be termites. A sound like crinkling cellophane could mean carpenter ants.

Cure: Call a pest control professional. 

4. Loud Knocking

Cause: If the knocking occurs when you turn off water, you have “water hammer,” caused when fast-moving water comes to a sudden stop and there is no air chamber (a short, specially designed piece of pipe) to cushion the shock wave. If knocking occurs when your furnace switches on or off, metal ducts are expanding or contracting as temperature changes.

Cure: If water pipes are the issue and there is an air chamber near the faucet, it may be filled with water and needs to be drained. You might be able to do this yourself. If you’re not confident tackling that or if there is no chamber, call a plumber to add one. Those snapping ducts? Just get used to them. There’s usually no cause for concern.

5. A Toilet Tank That Refills All on Its Own

Cause: Worn interior parts may be causing water to trickle through the toilet constantly, causing the water level in the tank to lower and eventually triggering the refill mechanism. A leaky toilet potentially wastes 1,500 gallons a month.

Cure: Untangle or loosen the chain — it may be too tight and preventing the flapper from seating fully, letting water leak out the flush valve. Or, try bending the tube connected to the float ball. If those don’t work, replace the valve and flapper inside the toilet tank (under $25 if you do it yourself, and a little more if you upgrade to a water-saving dual-flush valve).

6. Creaks and Groans

Cause: All houses creak and groan a little as parts expand and contract with temperature fluctuations and with changes in levels of humidity.

Cure: None is really necessary — it’s normal for house to make a few snaps and pops. But if a creaky floor is driving you batty, seek out an anti-squeak repair kit or dust some talcum powder into the seams where floorboards meet. The talcum acts as a lubricant to shush boards that rub together.

But don’t ignore really loud groans when there’s been an unusual amount of snow or rain, especially if your house has a flat roof. There may be an excessive or even dangerous amount of weight on your roof. If you suspect that may be the case, be prudent: Get everyone out of the house and call in a professional to check the roof.

7. Musty Odors

Cause: Mildew, a fungus, is growing because indoor air is humid enough to allow condensation to form on cold surfaces. Basements are favorite haunts for mildew.

Cure: Keep surfaces dry by one or more of these strategies:

  • Increase air movement with a fan
  • Keep relative humidity below 50% in summer and 40% in winter with a dehumidifier ($175 or so)
  • Make surfaces warmer by adding insulation

8. Rotten-Egg Smell When You Run Water

Cause: Bacteria that produce hydrogen sulfide gas (the scientific name for “rotten-egg smell”) are in your plumbing, or there is a problem with your water heater. Fill a glass with hot water, step away from the sink, and take a whiff; if you detect no sulfur smell, the bacteria are in the drain.

Cure: Disinfect the drain by pouring in a $1 bottle of 3% hydrogen peroxide solution, sold at drug stores. A sulfur smell in only hot water points to the water heater as the problem; call a plumber to disinfect the system or replace the tank’s magnesium anode. If hot and cold water both smell, call your water supplier (or health department if you have a well).