How do I verify that the HVAC partner is communicating with the e7w?

Use the PnG (Ping) parameter in Service Mode to ping a device with a defined address. Enter Service Mode, select PnG, press MODE, use UP/DOWN arrows to select the target device address, then press FAN to start pinging. A successful ping will display four parameter values in sequence: Device Type Code, Major SW Version, Minor SW Version, and AGC Level. (Page 56)