If you're DC is empty and if the humidifier unit is not a smart heater bar then you're better off unplugging it until the tech comes. Otherwise the humidifier will be running empty throwing up heat, instead of humidity.

You can easily learn how to replace the pads yourself. Nothing to it...

As usual in this forum, the participants have gone WAY off topic and failed to answer the original posters fundamental question. Her piano gets STICKY KEYS every 3-4 months, NOT an unstable soundboard or tuning issues. I would be very suspicious of a "piano tuner" who recommends a DC system to address this issue on a grand. However, a "whole house" or "room specific" system would definitely address the issue if the source of the problem was an excess of humidity in the environment and the subsequent swelling of organic materials in the instrument.

Usually sticking keys on a Kawai are in the key bushings although, it could be elsewhere too. They should be addressed and fixed with, or without a DC system. But, living in Michigan, I can't say what the norm is up there in Canada which is why I haven't addressed it.... Jurgen Goering could answer that one...

I think the larger point is that of all the typical culprits that one would look at as the source of "sticky keys", all reside within the action cavity, therefore, NONE would be adequately addressed by a DC system in a grand, since the DC unit resides under the soundboard and does not change the humidity conditions inside the action cavity to any appreciable degree.

I used to get sticky keys not from the bushings but from the piece of wood that sits in front of the keys that would swell. A little piece of cardboard put in there helped keep it from pressing up against the keys when played.

I'm not suggesting this is the problem, but there could be several possible reasons for sticky keys. I had a dammp-chaser on that piano and it didn't help that particular issue (nor was it installed to resolve that problem). If the OP's piano tech recommends it, however, I do think it's a worthwhile investment, and hopefully they did look at other possible causes for the sticky keys.

Actually CC2, this has all been responded to and was considered by the OP in replies. This was my initial advice. Please take the time to read what was written at the early part of the thread.

I did read it Marty, and your advice was misleading and essentially incorrect. The vast majority of "sticky key" issues stem from bushing expansion within the keys, NOT in the wippens and hammer shanks/flanges, and, since Kawai pianos with Millenium actions still use traditional keys and bushings, they are NOT immune to such problems, and ARE affected by changes in humidity from this perspective. That being the case, my suggestion to you would be to know what you are talking about before giving other members of this forum "advice".

""Sticky keys" generally are not a problem due to changes in RH with Kawai pianos. Is your piano tuner also a piano technician? It may be time for a full action regulation for your piano."

CC2 - Before you become accusatory, you might consider what I wrote as quoted above. We are in agreement but you seem to prefer to argue.

I too have installed hundreds of DC systems over the past 40 years and have had only positive results.

I think I can see that condo building from my porch...

In this kind of situation, I would investigate whether or not a humidity issue is indeed causing the problem, before recommending any multi-hundred dollar prescription. It could be something else entirely (and probably is). In our area, DC units are rarely needed, thanks to dry summers and mild winters.

A thorough look at the problem to come up with a definitive diagnosis should always be the first step. Actually, this should be the second step. The first step would be to get someone in who will diagnose before prescribing.

Thanks, Marty. I will be meeting with a tech soon, I hope. Right now I am travelling.

Another option is to forgo the DC's humidifier unit altogether and simply get a room humidifer and plug it into the DC control unit. Benefit is the humidifier will still only run when the piano needs it, you won't have to worry about opening the piano up to change pads, and the entire room the piano is in will be kept closer to the piano's ideal humidity level (unless you've got it in a huge room and would rather not pay $$$$ for a huge humidifier). Side benefit is that the room would also be more comfortable for people, too.

The Kawai actions stil have conventional action centers. They won't warp as wood does, but the felt action centers are identical to the ones installed in wood. Also, the Kawai actions still have wooden hammershanks reinforced with composite.

Solid action centers, like the old Steinway Teflon or the current Wessell Nickel and Gross actions (available for most pianos) have solid bushings with lower friction and no humidity response. I have installed the WN&G shanks/flanges with the carbon fiber shanks in new Kawai actions and gotten a noticeable improvement.

Actually, the DC system DOES affect the action cavity. It controls the humidity for the entire piano -- not just the part that it is adjacent to.

Most of the techs I've talked to in the Seattle area say a DC is completely unnecessary.

Blanket statements like these are problematic. It always comes down to a case-by-case evaluation. Example: An old piano with low-torque tuning pins sitting in an overheated seniors facility in Seattle, Vancouver or Victoria will definitely benefit from any kind of moisture it can get, that is for sure.

Every situation must be evaluated based on its unique conditions. That is where a forum falls short. Long distance diagnosis are usually speculative.

Luckily, there are local experts (and second opinions) available here, in contrast to many other parts of the world.

[/quote]I think I can see that condo building from my porch...

In this kind of situation, I would investigate whether or not a humidity issue is indeed causing the problem, before recommending any multi-hundred dollar prescription. It could be something else entirely (and probably is). In our area, DC units are rarely needed, thanks to dry summers and mild winters.

A thorough look at the problem to come up with a definitive diagnosis should always be the first step. Actually, this should be the second step. The first step would be to get someone in who will diagnose before prescribing. [/quote]

Yes, you're right.......... you probably can see this condo from your porch. So, can I give you a call and would you come over and give me a diagnosis?

I had a Yamaha G2 for 20 years in San Diego and Phoenix. The piano did not
have a Dampp-Chaser installed. Never had a problem with a cracked soundboard or excessive tunings. My two cents worth.

The first step is to spend about $30 and get a digital humidity meter (hygrometer). Don't get one of those dial-types that come with barometers; they're generally way off. Find one that stores the maximum and minimum readings. As Jurgen says, it's your individual situation that matters.

We normally hear about humidity on the weather report, where they measure it at the airport. Well, few people live at the airport, and it's your *indoor* humidity that your piano is experiencing. One piano in Phoenix may be fine, because there's refrigerated air conditioning, and the relative humidity never goes above 40% in the summer. Next door, a house may have evaporative cooling, and the piano may be suffering. Here in Albuquerque I've measured relative humidity as high as 70% with swamp coolers running!

So measure two things: the indoor humidity in the room where your piano lives, and then also measure your piano's pitch. If the piano is being affected by humidity changes, it will tell you, by how the pitch moves up or down. Most simple guitar tuner apps will measure the A above middle C and the one below it (which often changes pitch the most). You don't want to wait for a cracked soundboard as your first symptom.

--Cy--

Really......in a grand (which is what I stipulated in my response)? Please explain how a unit, residing on the underside of the soundboard, controls the humidity levels effectively in the action cavity to an appreciable degree. Is that what you tell your clients?

I've been curious about this too. If the case is closed up, the entire inside of the case will be a few degrees warmer than ambient, because the heaters are warming up the soundboard, which turns around and transmits that heat to the interior. I mean I know wood's an insulator, but it does eventually warm up. Less clear to me how the humidifier is going to get moisture into the action.

What I did was get one of these piano covers that reaches to the floor, so basically my piano, with its damp-chaser, is inside this little tent. I have one of these weather station remotes in side, and its telling me that the humidity is staying around 55%. (It's winter in Long Beach, which means the humidity outside is always about 70%.

I've actually conducted such an experiment because of comments like this made by Dampp Chaser distributors in the past. It was simple. I took the action out of the action cavity. I placed a humidistat in the cavity and one on the underside of the soundboard, then I covered the piano and left it for seven days. When I returned, the underside of the soundboard was 47%, the action cavity was EXACTLY the same as the ambient surrounding air in the room.

Lori822: Being able to see your condo building was a bit tongue in cheek...but yes. I tried sending you a PM (Private Message) but your current account settings do not allow this. Please contact me privately.
regards,

In the following thread are some actual data of my experience with the performance of the Piano Lifesaver made by Dampp Chaser. I am a satisfied owner of two units. Dampp Chaser Piano Lifesaver System Performance

These data demonstrate the increase in relative humidity above the soundboard and the increased stability of the relative humidity achieved, as compared with the ambient conditions of the room in which the piano is placed.

Your data are irrelevant to this conversation. The claim being made is that the Dampp Chaser can prevent sticky keys caused by excess humidity levels in a grand piano action cavity. Your sensors were placed between the treble tuning pins and the tail, which is in a separate compartment from the action cavity. Please explain how the DC unit, sitting under the soundboard, would have an affect on keys sticking.