Danfoss has developed a wireless communication system for which the typical wire-connected thermostats and controls are not needed. This modular hot water heating control system offers multi-zone control, using wireless thermostats (CFR) that send signals up to 100 feet to the master control (CFM) to process. The master control features an external alarm connection and can also be connected to the boiler controls for heating adjustment. Slave controls (CFS) and electric actuators (ABN) are also included. Danfoss.