Gas and Oil Home Heating Furnaces - Fan runs all the time - heat pump

I have recently had a new heat pump installed, both indoor and outdoor units. They did not replace the thermostat with the installation. The fan, which is set to 'Auto', never shuts off. This problem occured before the heat pump replacement as well. Is it safe to assume the problem lies with the thermostat? I've been told replacing a thermostat is not difficult as long as you are careful to re-wire exactly as it was before. However, if the problem is the thermostat wiring, will wiring a new programmable thermostat going to fix my problem?

shorted tstat wire. remove tstat and see if fan still runs. the installer should have looked at that during start up of your new system

It does sound like you could rule out wiring at the indoor unit if it was recently replaced. A competent contractor should have found this defect and suggested a remedy before leaving the premises. If the problem lies in the thermostat itself, it should be fixed when you replace the thermostat. If the problem is a shorted or pinched wire, it will still exist after you replace the thermostat. If you open the existing thermostat ans remove the green wire (fan wire) you can tell if it is a problem related to the thermostat. If the blower still runs, it is NOT the thermostat. Id you disconnect the thermostat and the blower stops, the problem is probably in the thermostat.