Leaking around the rim of shower head

[grazing cows]

We have a Vado shower with a rainfall shower head.
Every so often the hard water deposits clog the holes and I descale it - till the next time. Thinking I would attempt a longer lasting remedy, I took the whole shower head completely apart and soaked everything in descaler for several hours. It all looked fine and I put it back together again.
This morning, expecting a superb shower, I was devastated to find the leaking around the rim was far worse. No scale stopping the water just pouring out from around the rim!

Where did I go wrong? Should I have put a fine line of silicone around the disc with holes in before it went back into the chrome housing?

Any helpful suggestions will be greatly appreciated, thanks!

 

[Newboy]

The obvious answer - check that you have put it back together correctly and that any internal seals are in place/aligned.

It would be unlikely to have silicone sealant used as a part of the manufacturing process.

 

[Burnerman]

I'd guess an 'O' ring has been displaced somewhere?
John

 

[just pumps]

I'd guess an 'O' ring has been displaced somewhere?
John

Or overtightened so now distorted.