The Patterson-Kelley 10-0490-3516 Jumo Thermostat EM Series is a temperature control component designed to monitor and regulate operating temperatures in compatible heating equipment. It works by sensing temperature changes and adjusting the control circuit to maintain the required temperature range. This thermostat is used in Patterson-Kelley boilers and related commercial heating sy... https://www.partshnc.com/patterson-kelley-10-0490-3516-jumo-thermostat-em-series-95-210f