Heat Pumps and Electric Heating - changing thermostats

I have a white rodgers mercury themo now and was given a carrier digital thermo to change out. The only problem I am having is the B wire. The carrier does not call for a B and I was told that I was going to have to jump this wire to another. I do not want to blow up my system, for I was laid off from work and can not afford to replace entire unit. Any suggestions?

It is the E wire, not B. I was not told correctly which wire needs to be jumped or if it will work at all.

List what terminals are on your old t-stat and what wires are currently hooked to them and then list the available terminals of your new t-stat.

E terminal is emergency heat for heat pumps.

Jump W2 and E

This allows the electric heat strips to come on when Auxiliary heat is called for or when the heat pump is bypassed and just the electric heat strips are used in emergency heat.

The Carrier thermostat should also have a C terminal Common.
This terminal is important unless the thermostat purely runs off batteries.

Also do not miss wire the common terminal this could blow a fuse or your transformer in your Inside Unit.