On Thursday, April 12, 2018 at 4:44:03 PM UTC+1, Dave Plowman (News) wrote:

That suggests a dry joint somewhere - or a broken track which makes when
flexed.

My first approach would be to remove the board and re-flow all the joints.

Thanks, yes, I did have a go at the board years ago but these Suprima boards are very delicate and from reading of others experiences it's common to lift pads and even tracks. So I wanted to not molest this board further and keep it a known 'good' board.

The one I got from CET that didn't work in my boiler was pretty heavily reworked, with quite a lot of links and bridges. The latest one they sent was much 'cleaner' and worked fine.