Removed the thermostats from the wall upstairs, then installed them. The one in the main bedroom had a solid green light on it while the others were flashing for communication. Checked the blower and heating loop. The module is ok. After removing the thermostat in the bedroom and partially removing the battery and putting the thermostat back on the wall, the system started working. It appears the the bedroom thermostat was looking out the system. The controls are old and obsolete. Recommend replacing the controls.