Microprocessor PI control (NOT a limit control!) - One outdoor air sensor - One supply water sensor - The Taco Boiler Reset Control is a microprocessor based control designed to regulate the supply water temperature from a single boiler based on the outdoor temperature. To avoid boiler short cycling and large temperature swings, the PC700 is able to continuously adjust the boiler differential. Standard functions include warm weather shut down, minimum boiler supply temperature setting, and a starting water temperature setting. The updated Boiler Reset Control utilizes an easy to use automatic reset ratio calculation to set the relationship between outdoor temperature and supply water temperature (heating curve) to provide optimum control and comfort. The control has a liquid crystal display that clearly shows the boiler supply temperature as well as the other monitored temperatures and settings