Regular tuning and maintenance will keep your pipe organ in tune and reliable. There are many factors that can affect the tuning of an organ, and also cause minor problems such as cyphers (sticking notes), or notes to fail.
Changes in temperature and humidity are the main reasons for the tuning to move, and action problems to occur. Therefore it is advisable to have a pipe organ tuned at least twice a year. Once during the Summer, and again during the Winter while the Church heating is on.
The tuning is affected by temperature change due to slight expansion and contraction of the metal pipes, and also the change in the speed that the air travels up the pipe.
Action problems can occur due to timber parts shrinking or swelling. On pneumatic organs the leather can dry out, or become stiff depending on heat or dampness.