My husband and I noticed a few days a go, the house was still cold even after the thermostat was turned up to about 75 degrees. Neither does the unit automatically turn off.
We live in Texas so at any given day the temp may be 80 degrees today and 30 degrees the next day. As a matter of fact, we had a couple of 75-80 degree temps last week and this is when I noticed there was a problem. I'd turned the A/C on and set it about 72 degrees because I knew the temp was going to reach about 80 degrees later that day. My husband and I left the house, about 7a.m and returned about 6 p.m.that evening. When I walked in the house, it felt like and oven. Although I could hear the unit running, it was blowing warm air. I turned the thermostat to the "off" position and waited a few minutes before turning it back on. When I turned it back on I set the thermostat at 65 degrees. The temp in the house changed just "barely". It never got 65 degrees in side the house. So we finally turned the unit off again and used the ceiling fans for the remainder of the night. The following night, the temp dropped outside to about 40 degrees. I switched the thermostat from A/C to heat set the thermostat at about 70 degrees. The unit came on (automatically) during the night and ran constantly but the house was ice cold the next morning. After a couple of nights using a space heater AND panicking thinking about our electric bill!) I switched the thermostat to "Emergency Heat" setting and began using it. The house heated up immediately and the unit now comes on/turns off automatically. We've been running on the "Emergency Heat" mode for the past few days.

Can you tell by what I've describe what the problem could be? Are we damaging the unit running it on Emergency heat? Also, how long should we continue in the Emergency heat setting?

Mrs. J Robinson