To see this much rust on your
heaters, is a clear sign of moisture in the basement. Looking at the
basement walls, you will notice the staining and even mold growing on
the lower 3 feet of the walls. Is the moisture from the walls causing
the water heater and home heating system to rust?
In a situation like this, check the water heater for any water leaks first. If there are no leaks, there is a very good chance due to the excessive mold on the basement walls, that the problem lies with high levels of moisture accumulating in the basement.
Normally excessive moisture, whether it's an a basement, attic or certain parts of your house, the problem is from poor ventilation. If there is no air circulating in the basement, try to correct this problem by opening a window in the basement or installing a fan to circulate the air out of the basement.
Home Tip: Sometimes leaving a window cracked open can become a security problem. If you're afraid that someone will break into the home, then only cracked the windows open when you feel safe or are at home and try to position the fan near the window to blow the air out of the basement.
Crack the door open, that separates your home or living area from the basement to allow fresh air into the basement. If there are two windows in the basement, simply open the one window and install a fan in the other, that way, you won't need to leave the basement door to the home open.
There needs to be cross ventilation or an opening where air can enter and exit. If you have a fan blowing the air out of the basement through a window and no way for fresh air to enter the basement, it will take longer to remove the moist air.