Heat Pumps and Electric Heating - Heat APump won't stop pumpin' heat out!

We went away this weekend and upon our return, our house was 85 degrees inside...Changed thermostats to a programmable one, a Honeywell RTH 7400d but after installing it, Istill can't get the temperature down. Any quick advice...? I'm pretty sure I installed it correctly.. :alarm:

So, it started doing this after you hooked up the new stat ??

How is the new stat wire compared to the old one ???

Whoa nelly go back to your thermostat and pull off and isolate all wires except R G and C now if your condensing unit still runs constantly go to the condensor and replace the contactor as it has welded itself closed. If it shuts off reveiw your wiring diagram for the thermostat and wire it correctly. All a thermostat does is send voltage to the terminal that pulls in the heat or cool relay for your unit when it is called for by room temperature. G typically should be for blower C is typically common and R is typically 24 volts power from the transformer Heat will probably be a W and maybe a W1 aux heat and X or something will be for Reversing valve note some manufacturers swap things around and add crap so double check your particular heat pump. Assuming this is a HP? Is this the murphy of the infamous murphy's law?