Responded to a no-heat complaint in the garage and the space above the garage. Upon arrival, confirmed a call for heat from the thermostat and observed that the return piping for zone 1 was cold. Purged the zone and verified there were no freeze conditions. Confirmed proper water circulation through the zone. Observed the circulator intermittently cycling on and off despite a constant call for heat. Verified proper voltage at the relay board and at the circulator. Determined that the electrical plug at the circulator was not fully secured. Reseated the connector and verified secure connections at all remaining circulators. The system is operating properly at this time.
