The 255-620-A Automatic Refill System provides a simple method to automatically refill an evaporation pan at specified times. It consists of an electronic water timer and an automatic float valve. The water timer switches on at a user-specified time, allowing water from an external water source to flow into the pan. Works with low (gravity flow) or high (city) water pressure. The float valve will stop the water flow at approximately 8-1/2" to 9-1/2" depending upon the water pressure. The timer then shuts off until the next programmed time.