Freelander front offside wheel smoking hot

Hi I have a problem with front driver side wheel getting extremely hot on my 2005 freelander td4 I have fitted new caliper guide pins and applied copper grease to the back of brake pads which are new but I cant seem to fix the problem . I just went for a drive after a short time could smell the brakes, pulled into a lay by which was on a bit of a slope let the handbrake of and the car ran forward but the wheel was smoking with the heat any advice would be very much appreciated

Pistons sticking?

Pistons sticking or wheel bearing overheating?

Thanks didn't think of the piston sticking as it is fully retracted into the caliper but will check it out and the wheel bearing . thanks again