Trying to install a Honeywell RTH3100c to replace BDP 34427DP107 and have encountered a problem with wire compatiblility. Old thermostat has W1 (white wire), W2 (blue wire) and C (black wire) connections. On the new thermostat, I have E, AUX, L , B , and C as choices for my connections. How do I wire this?

hi

need to check the W1 if its connected on the system or not
if its connected on the system this stat will not work because then your system will be 3heat/1cool heatpup
this stat can only support 2H/1C heatpump
if W1 is not connected just tape off.
C-C
W2-Aux^E
W1 - check on system and work accordingly as suggested above.