Proper maintenance for your humidity control system is critical for proper function of the system.  The following steps must be followed to ensure proper function of your Dampp-Chaser humidity control system:

1)  The first and most obvious (yet frequently overlooked) maintenance item that a Dampp-Chaser system needs is a constant supply of power.  The unit should always be plugged into a wall outlet, and the outlet should not be controlled by a light switch.  In many cases, a piano will need to be re-tuned after the power supply to the humidity control system has been disrupted for more than a day.

2)  The next maintenance item that the owner needs to perform is to fill the humidifier with water when the yellow light (labeled “water”) begins to flash.  Fill the supplied watering jug with tap water to the red line, or to the line marked by your piano technician.  Then add one capful of the supplied humidifier treatment to the water in the jug.  Attach the watering jug to the watering tube.  Do not merely place the tube next to the jug spout, but push the tube over the spout.  Then hold the jug so that it is higher than the humidifier tank, and continue to pour the water until the jug is empty.  Remember, when the jug is empty, place the jug on the floor before disconnecting the watering tube. This will prevent water from draining back onto your floor.

Distilled water may be used in place of tap water, but the humidifier treatment must be added.  Failure to add the humidifier treatment will cause the yellow light to continue to flash even though the humidifier has been filled with water.  Also, try to remember to fill the jug with water first, and then add the treatment.  Forgetting to do this is not a serious problem, but the treatment will create excessive foam while the can is being filled.

Always be sure to use only the humidifier treatment manufactured by the Dampp-Chaser company.  Any other humidifier treatment will cause corrosion in the humidity control system.  If you run out of humidifier treatment, continue to fill the humidifier with tap water (not distilled water) and ask your technician to supply you with more humidifier treatment.

3)  The humidifier pads need to be replaced once per year.  This service is usually performed by the piano technician, but can also be performed by the owner.  Simply take the old pads off of the humidifier rod and replace using pads manufactured by the Dampp-Chaser company.  Some pads will need to be replaced more frequently due to high mineral content in the tap water.  Owners using filtered or distilled water should need to replace the pads less frequently, but the pads should at least be inspected for mineral build up.

4)  There may be a problem with the system if the red light (labeled “pads”) begins to flash.  Most of the time, the red light will flash after the yellow light has been flashing for several days.  Simply fill the humidifier with water, and the red light should stop flashing after about 15 minutes.  If the red light continues to flash for more than half an hour, call your piano technician, and do not unplug your humidity control system.  Usually, a continuously flashing red light indicates that the pads need to be changed, but could also indicate that the system has a defective part.

Frequently asked question:  “I had a Dampp-Chaser humidity control system installed on my piano, but my piano will not stay in tune.  Why?”

There are a few different reasons why your Dampp-Chaser humidity control system may not be working properly.  These are the most frequently encountered problems.

1)  Improper installation.  If your humidity control installer did not read and follow directions, the system will not function properly.  These are some pictures of improperly installed systems:  

Photo 1             Photo 2           Photo 3               (click photos to enlarge)

In photo 1, we see that the dehumidifier rod is about eight inches away from the humidistat.  The installation instructions clearly state that this distance is to be at least twelve inches.  In photo 2, we see that the distance between the humidifier tank and the humidistat is well over twelve inches, while the installation instructions call for six.  (The tank is at the bottom of the photo.)  Even worse, the humidifier and dehumidifier cords were switched, causing the system to do the opposite of its intended function.  The first two photos show a system that was installed on a Steinway concert grand piano.

In photo three, we again see that the dehumidifier rod is too close to the humidistat, and that the power cord is in contact with the rod.  Contact between the cord and the rod can cause the cord to become brittle and create a fire hazard.

This is why piano owners should use a Registered Piano Technician (RPT) to install a humidity control system or to provide any service for their piano.  An RPT has invested significant time and financial resources in training, credibility, and accountability that others have not.

2)  Improper maintenance.  Many times, piano technicians have not changed the humidifier pads, making proper humidification of the piano impossible.  Other times, owners have not ensured continuous power supply or timely replenishment of water for the humidifier.

3)  Defective parts.  Collins Piano Tuning takes extra measures to ensure that none of the components for the system are defective.  

4)  Too much air circulation.  A piano that is placed near an entrance that leads outdoors will not stay in tune, even with a humidity control system.  Also, be sure to close any vents and air returns that are within ten feet of the piano.  Never place the piano within ten feet of a fire place.

5)  Design problems in the piano.  Some grand pianos have pin blocks that are poorly fitted to the plate flange.  What is a pin block?  The pin block is the wooden component that holds the tuning pins.  In a grand piano, the humidity control system is placed under the sound board.  While this will control humidity for the sound board, it will not control humidity for the piano’s action and pin block.  If the pin block has been poorly fitted to the plate flange, it will warp and flex with changes in relative humidity, and the piano will not stay in tune.  On the other hand, if the pin block has been properly fitted to the plate flange, the plate flange will prevent the pin block from moving, and the piano’s tuning stability will be significantly improved.

These are pictures of poorly fitted pin blocks.  The steel ruler has been pushed in between the pin block and the plate flange.  The wooden component is the pin block, and the cast iron component on the other side of the ruler is the plate flange.  The ability to push the ruler between the block and flange indicates that a gap exists between these two components.  There should be none.

Dampp-Chaser indicator lights. 

Watering can, humidifier treatment.

Correct attachment.

Incorrect attachment.