What Causes Piano Keys to Stick?

Sticky piano keys are often the most common problem piano owners experience.  In Southern California, it is most likely to occur during the winter season. So what causes piano keys to stick and what can be done to solve the problem? One thing that causes piano keys to stick, is that something has become logged in between two adjacent keys. This can be anything from a broken off pencil lead, to a paperclip, to pieces of food such as rice, cereal, or any hard food crumb. Very often, young children love to put coins in between keys – dimes and pennies are common. This common problem is easy to spot, because it always involves two keys side-by-side. Push down on one, and its neighbor moves as well.

The remedy for this, of course, is to try and remove the unwanted object from between the keys. For very small objects, I’ve had good luck using an opened-up paper clip to pull it up and out from the keys. Just don’t drop the clip down in between the keys further adding to the problem. Bending it open should prevent this. If you just can’t get the object to move up and out, try very GENTLY pushing apart the two keys holding the object. This usually works well, but can sometimes result in the object dropping down under the keys. Honestly, this is usually not a problem. Many pianos live happily ever-after with all sorts of things hiding under their keys. You may want to ask your technician to remove the object from under the keys at your next service appointment.

Other common causes of sticking piano keys include:

  • Keys can warp and rub on each other
  • Keyslip rails can warp (the piece of wood in front of the keys can rub the key if too close)
  • broken keys
  • pens and pencils falling behind the fallboard on a grand piano
  • Keys can become tight on their balance rail and front rail pins. These hidden pins act as a guide and hold the key in place allowing it to rotate freely up and down, but very little side to side. When humidity drops, as it does during winter or Santa Ana wind conditions, the keys literally become slightly smaller and tighten down on the guide pins – sometimes to the point of sticking. This is very common on new pianos because tolerances between new parts have little to no wear and are more likely to bind.

Unfortunately, most of these other causes require the competent diagnostic and repair skills of your piano technician. So, if you’ve got a piano with sluggish or sticky keys, give me a call. I’d be happy to help relieve your frustration and make your piano play its best.