Monthly plumbing check

You absolutely, positively have to look for plumbing leaks. Obvious signs include visible water, dampness, or stains. Not-so-obvious ones are a sudden increase in your water bill, low water pressure, musty smells, or odd sounds. If you find any signs, don't ignore them. Figure out the cause. Fix that first, then repair or replace the damaged materials.

Note:
Sometimes pipes and plumbing fixtures may be wet or dripping with water, but are not leaking. This is condensation, or sometimes people say the pipes are sweating. It happens when the temperature of the pipe is lower than the dew point of the surrounding air. It often happens on cold water pipes on warm, humid days.

Another note:
Any water leak is bad, but there's a difference between a leak in a supply line vs. a leak in a drain line. Since supply lines carry water under pressure, any leak in a supply line can become a huge problem very quickly.

1. Change in water bill
If all of a sudden your water bill increases for no apparent reason, suspect a leak. Put your Sherlock Holmes hat on and start snooping around your house. Look at all the possibilities below.

If you’re on a well, it’s a little trickier, but since your well pump needs electricity, if you notice an unexplained increase in electricity usage, check to see how often your pump is running.

2. Low water pressure
Same goes for a change in water pressure. While there are other causes of low water pressure, a leak is one of them.

1. Under sinks
Look at pipes, connections, and the cabinet floor. Stains or peeling paint on the floor of the cabinet could be old or a slow, not-so-obvious leak. Put a piece of newspaper or a paper towel down and leave it for a day. If there are water stains on the paper, you know it's an active, but slow, leak.

Also, if you store any cleaning products under the sink, make sure they're closed tightly. Open containers of certain cleaning products can release corrosive particles into the air, potentially damaging some metals.

2. Around toilets
Check around the base of the toilet, as well as the hose connecting the water, and all connections. Step firmly about the base of the toilet to check for soft flooring, which might indicate water damage underneath. Also try to gently nudge the toilet to make sure it's securely fastened.

3. Water heater
Look around the base of the water heater, the pipes connecting the water, and all connections.

4. Floor around dishwasher or refrigerator with ice maker/water dispenser
Refrigerator water dispensers are notorious for leaking. Check the floor in front of the dishwasher and refrigerator for signs of water damage (stains, soft or swollen flooring).

5. Clothes washer hoses
A bulge in a rubber hose can indicate an impending leak. Don't ignore it! Most plumbers recommend replacing rubber hoses and using braided stainless steel hoses on a clothes washer. Bonus points for using braided stainless steel hoses with auto-shutoff. With either type of hose, most recommend replacing them every 3-5 years regardless of their condition.

6. Any exposed plumbing pipes
Look at the pipes and especially the connections for dampness or water. See the note above about condensation on pipes. Different pipe materials have different pros/cons and things to look for. Check out this article for more info. 

7. Ceilings/walls under or around any water-using appliance or plumbing fixture
Look for stains, peeling paint, bubbling wallpaper, swollen drywall, soft walls, mold or mildew, or musty smells. If a stain has been there a while, it might be from an old and since-repaired leak. But if it's new, investigate the cause. Same goes for any of the other conditions. 

When looking at all the areas above for signs of active leaks, also look for indicators of potential future leaks, such as corrosion on the outside of pipes, rust spots, or bulging hoses. Replace any pipes or hoses showing these signs.