The Honeywell CM900 Wireless (CM927 or CM921) is a modern wireless programmable room thermostat based on Honeywell’s proven programming philosophy. To further improve the ease of use, this product includes an extra large LCD display with backlighting and LoT Technology to assist customers during daily use.The CM927/921 room thermostat communicates with the BDR91 Relay Box … Continue reading Honeywell Thermostat CM900 User Manual