Ferroli Modena 102 DHW continuously turning off and on?

Hello all

This problem has been going on for about 12 months now and I've completely fed up of doing the hokey cokey in the shower.

I have already replaced the DHW sensor as this was the first thing suggested to me, but it turns out this hasn't helped.

The problem seems to be far worse in winter as well!?!

The other reason could be that my main board is screwed, but I'd like to try everything else before I admit it.

The manual for the Modena can be found here http://www.ferroli.co.uk/product_documentation/DOMESTIC_ARCHIVE/Modena_102_Manual.pdf

I can solder, if anyone can think of anything that may need replacing on the main board, and I think I have a voltmeter somewhere should anyone need me to take any readings.

Many thanks in advance