Symptoms
- Pressing the left pedal makes no difference to the volume or tone
- The pedal feels loose, floppy or stays down
- On a grand the keyboard doesn't shift sideways when you press it
- The pedal clunks or the keyboard shifts unevenly or sticks
Likely causes
Disconnected rod or dowel
On uprights a dowel or rod links the pedal to the hammer rail; on grands a rod pushes the keyframe sideways. If it falls out or slips, the pedal does nothing.
Broken or weak return spring
Without its spring the pedal may stay down, or the grand's action may not return to center.
Out of adjustment
If the travel is set too short, the hammer rail or action barely moves, so you hear little difference.
Hammers already very hard or worn
On a grand, una corda relies on the hammers hitting a less-worn part of the felt. Very worn or hard hammers reduce the difference you hear.
What you can safely check yourself
- 1On an upright, open the lid and watch the hammer rail: when you press the left pedal, the hammers should all move forward towards the strings.
- 2On a grand, watch the keyboard: it should slide a few millimetres to the right when you press the pedal and return when you release it.
- 3On an upright, remove the lower front panel and check that the dowel or rod for the left pedal is in place and the spring is attached.
- 4On a grand, check the pedal lyre and its braces underneath and look for a rod that has dropped out.
- 5If you have a middle pedal, check you are not confusing it with the practice mute or sostenuto.
What not to do
- Don't push the grand's keyboard sideways by hand to 'help' it; you can damage the keyframe or action.
- Don't remove the action or keyboard yourself.
- Don't lubricate the action or keyframe with sprays.
Quick fixes vs. call a pro
You can usually handle it
- Check whether the hammers or keyboard move
- Reseat a dowel that has fallen out
- Check the grand's lyre braces
- Confirm which pedal does what
Call a technician
- Replace broken springs or rods
- Adjust the shift or rail travel
- Fix a sticking keyframe on a grand
- Voice hammers so the pedal is effective
What a technician will do
A technician reconnects or replaces the linkage, adjusts how far the hammer rail or action moves, and on a grand makes sure the keyframe slides freely and returns to center with the hammers striking the correct strings. Simple reconnections take minutes; adjusting the shift and voicing the hammers for a real una corda effect takes longer and is often done with a tuning.
A piano holds about 18–20 tonnes of string tension. If a fix means opening the action, turning tuning pins or working near the strings, leave it to a technician.