A reader writes “i have a 2000 clayton home and i wet spot in the master bedroom doorway where the carpet meets the tile but i can not find the water leak. checked under the house no signs of water leaking all dry. the spot was wet for a day or two and dried up and was gone for a couple of weeks but now has come back and has been wet for a few days. is it possible that the water heater is leaking from the closet and only getting wet in that one spot. i am at my wits end and can not find where the water is coming from.”
You home is old enough that if the water heater has not been replaced it could be beginning to fail. Can you slide a cookie sheet or some other non-flammable material under the water heater and check if for drips?
Has it been warm and humid enough where you live for condensation from the A/C to be a problem?
Water leaks can be tricky because if they are slow there not be any visible drips. The water will run along a supply line until it touches something. You may not be able to see a leak because it is getting out of sight before it leaves any traces.
Try touching any nearby supply lines and see if your finger tips get wet. You can also look for lime deposits on supply lines or at connection points.