Sticky Piano Keys: Causes and What Fixes Cost

A sticking piano key is almost never a serious problem — and it's almost never a reason to stop playing. In most cases the cause is one of five things: humidity swelling the wood, a small object fallen between the keys, a worn or dirty key bushing, a warped key rubbing its neighbour, or a problem in the action behind the key. Some of these you can safely check yourself. The rest is a quick fix for a technician, usually handled during a regular tuning visit.

Here's how to tell which one you're dealing with.

First, check the simple things

Before anything else, look for the obvious culprits — they account for a surprising share of "broken" keys we're called out for.

Something's fallen in. Coins, hairpins, Lego, pencil ends, guitar picks. Anything small enough to slip between the keys will eventually do exactly that, and it wedges the key so it can't move freely. Shine a flashlight into the gap on either side of the sticking key. If you can see the object, you may be able to lift it out with tweezers. Don't pry the key itself.

Sticky spills. Juice or coffee on the keyboard works its way down the sides of the keys and dries tacky. If the key resists on the way down and the way up, and the piano lives in a family home, a spill is a good bet. This one usually needs a technician — the key has to come out to be cleaned properly.

The fallboard or key slip is rubbing. Sometimes it isn't the key at all: the strip of wood in front of the keys shifts and presses against them. If several neighbouring keys all feel sluggish, gently check whether the front rail or fallboard has moved.

The most common cause in the GTA: humidity

Piano keys are wood, and wood swells when the air is damp. In Toronto's humid summers, the felt bushings inside each key tighten around their guide pins, and keys start returning slowly or sticking down. The same piano is often fine again by January, when furnace heat dries everything out.

If your sticking keys arrived with summer, humidity is the likely cause. A technician eases the bushings in a few minutes — and if it happens every year, the real fix is controlling the room's humidity. We've written a full guide on the best humidity level for a piano in Ontario.

Causes that need a technician

Worn or compressed bushings. Each key pivots and slides on felt bushings. After decades of playing they wear, compress, or gum up, and the key wobbles or drags. Easing or replacing bushings is routine work.

A warped key. Keys are long, thin pieces of wood. One that's warped slightly rubs its neighbour on the way down. The fix is careful adjustment — not something to attempt with sandpaper on a Saturday afternoon.

Trouble in the action. Behind every key sit dozens of moving parts. A loose flange screw, a sluggish jack spring, or a hammer rubbing its neighbour can all masquerade as a "sticky key." This is precision work, and it's exactly what a service visit is for.

What repairs cost

Most sticky keys are a minutes-long fix, and if we're already at your piano for a tuning, minor adjustments like this are typically handled on the spot as part of the visit. If the key problem is the whole reason for the call, our service call is $115 + HST (currently $75 on intro rates), which covers the assessment and minor adjustments. Bigger jobs — a full set of bushings, action regulation — get an honest written estimate before any work begins, and we'll tell you plainly if an aging piano isn't worth the spend.

What we'd caution against is forcing the key, working it violently up and down, or spraying lubricant into the keyboard. WD-40 and piano felt are enemies for life; a two-minute repair can become a much bigger one.

Common questions

Can I fix a sticky piano key myself?
If it's a visible object between the keys, yes — flashlight and tweezers. Anything involving removing keys, adjusting the action, or lubricating parts should go to a technician. Pianos are forgiving instruments, but the action is not a DIY zone.

Why do my piano keys stick in summer but not winter?
Humidity. Damp summer air swells the wooden keys and tightens the felt bushings; dry winter heating shrinks them back. Consistent room humidity (ideally around 40–50%) solves it for good.

Is a sticking key a sign my piano is failing?
Almost never. It's one of the most routine issues in piano service — closer to a squeaky door hinge than a failing engine. Have it looked at during your next tuning or repair visit and keep playing in the meantime.