Upon arrival system was off home owner stated that system was cooling past set temperature at thermostat. We entered from the back of the home and I noticed right away that condenser coils were dirty. I turned system on to see if issue was still happening. Customer stated that they recently changed air filter and issue was still ongoing. Temperature in the home dropped below thermostat ask, and was continuing to drop with system continuing to cool. Checked 24 volts and was still getting a call for cooling even though thermostat was satisfied. I recommended new thermostat and condenser coil cleaning Installed new thermostat and programmed with correct unit settings for heat pump. Checked Delta and was at 19 with system running for 5 mins Went outside and cleaned condenser coils from inside out. Tested system to make sure it shut off after thermostat satisfied and it did. System was left on cool at 73 on departure per home owner request.