Trane 1000XE only blowing hot air when set to cool
10 yr. old Trane 1000Xe was cooling fine during the summer. It was even checked out by a professional A/C tech, who found it to be working Ok back in July. Two weeks ago we had to use the heat for a couple of days, and then we were able to go with out using the A/C at all for a week. The weather warmed back up and we turned the A/C back on to cool off when we discovered that it would only blow hot air, even when set at the coldest setting. Both Airhandler and outside unit is working, and the comprssor is running too, but I found that both copper lines were extremely hot and that they seemed to cycle between hot and ambient cool. Please help.