My local church has an upright accoustic Bechstein piano. The keys are so light and have no weight to them at all. It feels like there are no strings to this piano. How have the keys gone like this?

Without seeing it, there's no telling.

Uprights are generally categorized by height, because the height has a huge effect on the actual construction of the piano. Uprights will often have lighter actions anyway, as you aren't necessarily working against gravity. But if the piano is very short, it may have a spinet action and those tend to feel pretty 'mushy' to me.

Bechsteins have a light action, and are very noisy instruments! You cannot turn `em down . . . well, I can`t anyway! But they must be pretty good; everybody says so except me . . .

I came across a very light action like this when I was testing out some various pianos for acquisition recently. Actually, I quite liked it. It seemed like it was easier to play and it was still very responsive. I do like a light action, but not too light (the one I tried I think was too light) so as not to be overwhelmed if ever transitioning to a much stiffer action like many grands.

I think it is by design though and not something that happened to it. Some will prefer it.

That sounds unusual for a Bechstein to me. I have a Bechstein grand, and it has a very responsive, but firm action. It also has a very mellow tone and is not very loud or bright. I live in an apartment building so I chose it for its subdued voice. They have a Bechstein upright in one of the practice rooms that I go to and it has a nice action also. It sounds like the piano you played needs some TLC!

I can confirm Bechstien pianos are a very light action.

The concert grand I encountered in Liverpool that got trashed was considerably lighter on the action than my casio.

It filled the room as it was deafeningly loud.

I found a second one in poor condition untuned and a ton of sunken keys it too had a very light action.

You could make an offer to your church for this piano . . . I`m sure you`ll be able to make it a cracker! Like, putting a piece of cloth between the strings and the hammers . . . I think it would make it sound quite good . .