The number one reason fountain pumps fail is lack of water. These pumps are magnetic drive pumps and are water cooled. If the pump is not fully under water when running at all times, it will burn out in just a few hours. Many customer have found that their pumps are placed just under the level of the water and that over the matter of days or a week the water level will drop from evaporation and will start sucking in a little air with the water. This makes the pump run hot and greatly shortens the life. If the water is allowed to drop even further and the pump pulls in too much air then it burns out very quickly. Keeping the water level full in your fountain is the best way to ensure long life for your pump.
The second most frequent cause of pump failure is too frequent cycles for the pump. This type of pump will often run for 7-10 years straight when run 24 hours a day. The more on and off cycles a pump experiences the faster it fails. Now setting the pump on a timer to come on for 8-12 hours and then turn off will not greatly effect the life of the pump. However, if the pump is set on a timer to come on and off every hour or so then it will shorten the life of the pump as the most strain on a pump motor is during the start cycle.
Hopefully the above information will be on some use to you and will help you keep your new pump happy and healthy for years to come.
Graystone Industries, Inc.