When I depress the Examplesustain pedal, the first time I press any key there is a click. This doesn’t happen if the damper pedal is not engaged. If you keep the damper engaged it will not click on the second press of the same key or any subsequent press (just the first). Release the damper and reengage it and again the first press of any key has a click. Linked here is a video showing this. Any ideas?

My first guess is that something is moving part of the mechanism slightly, and that it clicks back in place when you press the key. But it's impossible to check where sounds come from with a video.

It seems reasonably reproducable. I suggest asking a good tech. Maybe he needs a stethoscope to locate it.

Does this happen when the muting pedal is not activated?

Yes it happens when the mute pedal is not engaged. Just did that so it wouldn’t pop the phone microphone

The sound is definitely somewhere in the action. I have ruled out it being key noise.

What about the keys at the top where there are no dampers? Does it happen with those when the pedal is depressed?
How many pedals does your piano have?
Nick

3 pedals and it doesn’t appear to do it with the top keys but I suspect the click would be around those frequency’s so it may just be hard to hear it. That said I’m convinced based on the above it has something to do with the damper

Since this is a new piano, it might be something as basic as a loose screw. Has it had its first service from the dealer? Whether or not, the dealer should sort this out.

Thanks. Tech is coming in a week or so. I’m just hoping it’s fixable!

Chances are the middle pedal needs adjusting...it interacts with the damper tails.
That's my bet. So please let us know.
Nick

Will do. Thanks!

Let me assure you that no matter WHAT it is (and I REALLY have NO clue) it IS fixable, period.
I'm gonna go out on a very sturdy limb and say it is *impossible* that it even *might* be unfixable, based on your description.
This is NOT the sort of symptom of an unfixable problem.

Great. That makes me feel better. I still have two weeks until the tech comes!

Please report back of the cause and the solution when you know it.

Yes, please keep us updated. My U1, which is just over 1 year old has started to do the same thing. I think I've narrowed it down to the rubber post that connects the damper pedal to the action, but the rubber itself seems fine.

The click was absent in both the action and the pedal when the technician was over and took the piano apart.

I suppose it could be the middle pedal as well. The noise went away if I pressed the damper vertical rod to the left or right, which I assume meant that I was pressing the rod against the rubber and alleviating the click.

Noises as you know can be hard to track down. I own a U1 about 40 yrs old. The past almost year at times when playing I'd hear a knock sound in bass area when playing occasionally. Hard to describe. Came and went as it pleased.
So, eventually a bass string broke down near the bridge. Replaced it and so far no knock sound.
Can only think it took its time breaking getting weaker and it created the sound. I don't know really.
Strange.

So, finally fixed and I’m embarrassed to say it was just where the damper was set. It was way off - too much lost motion. That said, the tech acknowledged the click on just the first hit of each note, but could make sense out of how correcting the damper pedal (adjusting it) resolved the issue. Any ideas?

Still sounds like the sostenuto tongues to me.

A U1 does not have sostenuto.

Ahh... I'm wrong again! Keeps happening...

What a wonderful problem, and an excellent video. I love that it's so reproducible in such specific ways.

I feel like it has to be something related to the damper levers.

Here are some ideas for narrowing it down further:
1. I thought I heard an extra click in the video when you released and reset the damper pedal. Does that always happen? What if you haven't played any keys?
2. You can eliminate the possibility of it being in the keys if you use your finger to press up on the wippen (the part that the sticker on the back of the key contacts.) Play the notes without moving the keys
3. Does this happen even if you press the key so slowly that the note doesn't play? Try pressing the key down so slowly that it takes 5 seconds to get to the bottom. Any resistance when the click happens?
4. Now try to eliminate the rest of the action. Press the damper pedal and reach over and in front of the hammers with your finger, and grab the top of a damper with your fingernail. Pull it gently away from the strings. Any clicks? Any resistance?

Is there anything non-standard about this piano? Player system? Silent/headphone mode? Sorento pedal?

They do have a sostenuto at my local huge yanaha store! Maybe the older ones didn't?

You've made me admit to being stupid when I'm not! I reserve that position for my wife!!

So, in an early post I predict sostenuto interference with the damper tail and I stand by that.
That's what it will be, for sure.
Nick

They may have sostenuto in the UK, but not in the US.

Just to report in, my issue with 2020 Yamaha U1, clicking damper pedal was the hinges of the action activated by the pedal. Piano technician used whatever special lubricant that was needed, and it solved the issue. He had to remove one of the hammers to access one of the hinges.

I hope this helps someone in the future!