LG washerdryer

customer reports poor drying. first question is there any way to skip the pre spin on the dry only programe. when it eventually does dry, heater works fan works no obvious blockages valve meters ok but no volts let it run about three or four mins but didnt want to let it run too long to damage the microtemp. does the valve kick in via temp sensor? is there any common faults on these ? I dont see too many of these

thanks wilf