PROBLEMS ASSOCIATED WITH CONDITIONS ALTERNATING BETWEEN BEING TOO HOT AND DRY, AND THEN TOO COLD AND DAMP
Therefore, those who keep their piano next to a hot radiator, or in a bay window which is South-facing, or in a room with an efficient wood-burning stove, is to ask for trouble. Also, under-floor heating can lead to significant problems – one can purchase specialist mats to protect both upright and grand pianos from under-floor heating.
Any acoustic piano kept in conditions where the temperature is regularly in excess of 80 degrees Fahrenheit (27 degrees centigrade/Celsius) will suffer from the following problems: (a) The piano goes out of tune quickly; (b) Sooner or later, the soundboard will crack in one or several places, giving rise to rattles and buzzes when playing certain notes – soundboard repairs are extremely expensive; (c) The tuning pins (known also as wrest pins) will become loose because the wooden pin-block (also known as the wrest-plank) into which the tuning pins are seated will dry out, and may even develop splits, thus making the piano go out of tune very quickly indeed, or even make it impossible to make it stay in tune; (d) The hammer flange screws and lever flange screws will become loose, causing rattles and even hammers to strike the wrong strings (causing incorrect hammer alignment); (e) The centre-pins connecting the hammers to the flanges, and levers to the flanges, may become loose in the flange bushings, causing rattles and wobbling hammers; (f) The keys themselves will dry out and rattle when playing.