Checked over the system. Found the Subcooling low which would cause the system to freeze. I also found a bad blower relay which is causing the blower to run all the time and the electric heater is running due to a bad heater relay. The customer has a January electric bill of $609.47 and a December electric bill of $432.76 The system is 15 years old and in poor condition. I'd recommend having the system replaced.