A circulation pump will run continuously until the water temperature is 1°F above the programmed temperature setting. When at the correct temperature it will turn off and back on every 30 minutes and circulate for 1 minute or to heat the water as needed.
Circulation pumps are used to save energy and help attain better water quality. These pumps pull from the filter and push through the heater in a constant flow of water. This circulation keeps the water clearer, as it is always moving through the filter media.