I had this problem with my suprima 50. Following advice on one of these forums I removed the PCB ( 5 minute job - really) and checked the soldered joints on the back of the PCB. There were several 'dry joints' , joints with hairline cracks in the solder - very difficult to see. These dry...
I have had awful problems with my suprima 50 for more than a year. The boiler would trip out more than 10 times a day ( flashing red light). - it drove us mad.
Potterton wanted more than £200 to change the PCB ( the main cause of these Suprima problems ) but I hated the idea of paying them...
