Honeywell RTH6500WF - Troubleshooting; Error Codes E42, E43, & E99

69-2718ES—01 60
Troubleshooting
M33998
Error Code Action
E42
Router is not issuing
an IP address to the
thermostat.
• Waitfor30minutes,connectioncan
take several minutes.
• Ifstillnoconnection,remove
thermostat from wallplate for 10
seconds, then reconnect it (see page
26).
• Verifyyourrouteriscorrectlysetupto
automatically give IP addresses.
E43
No internet connection.
Thermostat cannot
communicate to Total
Connect Comfort.
• MakesuretheInternetcableis
plugged in.
• Reboottherouter.
E99
General error Remove thermostat from wallplate for
10 seconds, then reconnect it (see
page
26).