I recently installed the Nest Learning Thermostat and am having the following issue:
- The heat comes on properly and the furnace runs for usually 5 minutes at which point the thermostat indicates that heating is complete (even thought the set temperature has not been reached). The Nest App then shows “E73: No power to Rc wire”
- After about one minute the thermostat indicates that heat is coming back on (even though it never stopped). At this time the Nest App also goes back to functioning normally (E73 is gone). During this one minute of “downtime” on the thermostat and Nest App, the furnace is running
Even though the temperature eventually reaches the set point, the intermittent malfunction on the thermostat and the E73 on the app are concerning. During a longer heat cycle this happens 3-4 times.
I have a C wire hooked up. I have tried everything that is typically recommended online for E73 issues (fuse is fine, wires are fine, furnace connection is fine). I even tried swapping the thermostat for another Nest Learning Thermostat and still no luck.
