Air Conditioning - Compressor does not shut down

We have a Bryant Model 663C heat pump. We normally run the fan all the time. We noticed 3 days ago that the house temperature was getting below the set temp on thermostat. I turned the fan to automatic. We came home after leaving for the weekend today and saw ice on the large lines coming to the unit in the house. I also noticed ice on the lines inside the compressor unit on the outside of the house. I turned the system to heat and after a few minutes, the ice was gone and temperature was going up. Decided to shut it off. This is when I noticed the compressor on the outside of the house continues to run. I guess that is why it was cooling so much and iced up when I shut down the fan. What can be causing this? If I just trip the breaker to shut everything down, will it cause a problem?

We just happen to have a service tech coming in for a normally scheduled fall maintenance this week but I would like to know what I should do in the mean time and do not want to pay the premium for someone to come in on an emergency repair. Would also like to be armed with as much information as possible.

Thank you

Your CONTACTOR may be defective (stuck on) or your thermostat may be not working properly.
In most cases, running the blower constantly doesn't do much except wear out the blower motor.
Running your AHU fan constantly wears the motor out and stops up your air filters sooner than normal.
If you just want air circulation use a 20 buck box fan or a ceiling fan.