There was a post by ACETC back on August 3rd 2007 that confirms my question, but I bypassed it by doing this and I need to know if it is safe. I just bought a house and replaced the old thermostat with a new one. The old configuration was, RH/RC jumped, White wire in O, G, Y, and blue which is cut off. On the new one I have W, Y, RH, RC, G. So on the new one I plugged into RH and jumped to RC, yellow in yellow, green in green, and white into white (since O is not an option on the new one). When I did this the unit turned on but was spitting hot air.

What I did to bypass that was jumped the Y and W together which in turn started putting out cold air. My question is, is this safe and in the winter, will my heater work?

According to ACETC he (or she) said to buy a new T-stat that works with heat pumps, the guy did that saying it worked. Thanks for any help!

My question is, is this safe and in the winter, will my heater work?

It is not correct. Buy the correct thermostat. If you have a heat pump buy a heat pump thermostat.

How do I know if I have a heat pump or not? First time home buyer and not so sure about this kind of stuff? Even though its not "correct", if it works and there is no harm in doing it, then why not?

My question is, is this safe and in the winter, will my heater work?

It is not correct. Buy the correct thermostat. If you have a heat pump buy a heat pump thermostat.

How do I know if I have a heat pump or not? First time home buyer and not so sure about this kind of stuff? Even though its not "correct", if it works and there is no harm in doing it, then why not?

The outside unit runs in heat and cool mode.
Lookup by model number
The presence of a reversing valve in outside unit

Buy the right thermostat otherwise the heat pump could run forever and never shut off. You might come home to a toasy house one day or a freezer.