How to Resolve the ER2 Message on the Terra Smart WiFi Thermostat?

When the thermostat reads “ER2,” the floor sensor has a short circuit or has a loose connection. Your electrician must secure connections and test the probe using a multimeter set to the lowest possible ohms scale. The resistance reading should be between 7 and 17 ohms.  If a short is found and a backup sensor probe was not installed, you can bypass the error message by setting the thermostat to read the air temperature instead.

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