Thanks for all the replies. Just to confirm it's Card Reader 2 I'm using, as I said in the first line of the thread
![Wink :wink:](./images/smilies/wink.gif)
Anyway, it's always been a bit tempremental connection-wise, but got worse when I got a new phone and installed the new app. I'd been using the old version of the app on my old phone.
So I've been swapping my sim between my old phone and new one, and to complicate things there was a fault with the new phone, so had to return that yesterday
So I've reinstalled the new Zettle app several times over the last couple of weeks, and reinstalled it a couple of hours ago on the replacement new phone.
App installs easy-peasy, and pairs with the card reader OK. So that went fine, and it was connecting OK to make a transaction.
But after leaving it for just 15 minutes, I retried it, and it just wouldn't connect. App often says to press the power button on the card reader, when the reader is obviously active, and pressing the power button doesn't seem to help anyway.
Then tried unparing them, then pairing them again, and that was fine. And it did work about half an hour later, so it just seems to randomly not want to connect. (And the app says the card reader software is up to date.)
Not perfect on my old phone, but seems to work slightly better on my old phone with the older version of the app.
Anyway, looks like I'll have to try Zettle support, but the card reader is a couple of years old now, and certainly don't want to buy a new one if it's faulty.
So might have to give SumUp a try...