I took the specs from the Balboa M7 technical service manual, link enclosed, page 20.
https://www.hottubdiy.co.uk/user/Manuals/Balbo_M7_guide.pdf
I appreciate small margins can make a difference hence why I replaced them along with the heater.
I have a new 2 speed pump arriving today but am leaning toward an issue with the board.
My understanding of test mode is that pressing ‘light’ and ‘temp’ should display the values for both sensors alternately.
However my system do not and only shows one sensor value continuously, a reversed ‘b’ which I assume is sensor b. Tried to find a video of it just to check I’m doing it correctly.