Water fountains make a lovely, soothing accessory to any garden, indoors or out. Most fountain pumps will run for years with little or no maintenance so long as they're kept free of debris and have adequate water. The most common fountain pump problem--and about the only one that can be fixed at home--is when the pump freezes up because of accumulated debris.
Turn the fountain off and remove the pump.
Wipe the pump cover off with a damp rag. Soak it in white vinegar, if necessary, to remove any hard water or other difficult stains.
Use a butter knife or other dull, thin object to pry the pump cover off. Pull the magnetic impeller straight out; if the pump is very small, you may need a pair of tweezers to do this. Set the impeller aside where it won't get lost.
Remove the tubing from the pump outlet and check for any obstructions; remove anything you find with tweezers. Rinse the tubing out and soak it in white vinegar, if necessary, to get it clean.
Wipe any debris away from inside the pump, using tweezers to reach inside the impeller cavity if necessary. An old toothbrush may be useful for reaching awkward places on a large fountain pump. Rinse the pump out with water. Add a single drop of liquid dish soap.
Reassemble the pump immediately. Place it in a basin of water or, if necessary for it to run, back in the fountain (which should them be filled with water). Run the pump for several minutes. The dish soap will lubricate its moving parts and, if the pump was frozen up completely, may get it moving again.
Turn the pump off, empty the basin or fountain of the soapy water, and refill with clean water. Run the pump once again for a few minutes. If there are any signs of soap in the water, empty and refill the fountain once more.