If your piano breaks a string while I’m tuning it I will have to make a second visit to re-string it. Leaving a string off can cause uneven wear to the hammer felt causing more regulating work in the long run, so the best course of action is  to put another string on the piano as soon as possible. This is just something that happens from time to time (it’s not the fault of the piano tuner!), every piano will break a string or two in its lifetime. Luckily re-stringing is a fairly quick and simple job. At the end of a piano tuning session I will measure the string with a micrometre so I can gauge the correct size (piano strings come in different sizes unfortunatley). I will ask to make another visit in a few weeks time (I will have to order a new piano string and wait for the delivery) and on that visit I will charge you the price I paid for the new string.
Pianos aren’t re-strung all at once in the way string instruments usually are. Piano strings are much thicker and strung at a higher tension. A piano tuner/technician may decide to re-string the copper bass strings if they begin to rust and lose tonal quality, but as a rule, piano strings are only replaced individually when necessary.

[Sorry for the rushed post, I’ve just finished my morning piano tuning in Sheffield and I’m about to leave for a weekend of piano tuning in Scarborough. I might go into this in more detail in a future post, but I think most customers get the gist of the re-stringing process from this post.]

– Richard, Piano Tuner Sheffield.