hello, my family moved into a new home in June. Our wf envision was installed 10 years ago and still retains 10 months of warranty. The home was built in 1997. The system ran fine until mid November. Temps in the 20's. Then I noticed it started running constantly in the aux 2 setting. It never reached the setting of 70 degrees. Our electricity bill was outrageous. The house will maintain a Temp of 67 for 2 hours before the furnace turns back on, so I would say that the home is decently insulated. I called the company that installed it and they said that the thermostat is bad and disconnected the emergency heat element. I have a new thermostat on order(not warrantied). Currently we have output air temps at 94 degrees at the plentum. Return air is 2-3 degrees lower than the thermostat reading. Currently our outside temp is below zero at night. The furnace Runs constantly and the inside temp falls to 61 at night. It will heat to 65 during the day. The furnace will not reach a setting of 67 degrees. The heat is exchange was replaced 5 years ago under warranty. Am I expecting too much out of the furnace for it to reach 70 degrees in zero degree weather? Is 94 degrees at the plentum an acceptable output while running just the heat pump? I've noticed that the compressor seems louder than it did last month. One odd thing that I've noticed is if I have the thermostat set at 68 and the temp reading is 67, if I turn the setting down to 66 to give the furnace a break the temperature reading will also drop to 66. I have to drop it 2 degrees for it to shut off. Thanks for your help.