It is very important that the inside of the piano is checked. Pins used under the keys are called the balance & front pins, very often they are rusted due to lack of climate- control. Removing rust and appropriate cleaning, reduces friction so that the touch will be smoother. Piano manufacturers suggest that the ideal humidity level for pianos is about 45-60%.
*Please try to keep the piano with humidity level at least less than 68% in your room.