Through further communication with Potterton most recent letter (on Roger's website) I have finally got them to investigate why there PCB fails. From the information I / the residents of Cambourne have provided, it has assisted Potterton in the future redesign of the PCB board. The low voltage that occurred during these powercuts (measured at 138V) causes a pump relay to switch rapidly on and off, eventually this welds into position. Therefore I believe some limited success has been achieved. Again Potterton Board is currently designed to meet the current European Standards i.e. minimum voltage of 195V. However it seems 24/7 (now EDF Energy changed name recently) have a obligation to supply greater than 195V this is only valid for 95% of the time. Therefore Potterton intend to fix there board to cope for the 5% time 24/7 are allowed to drop below 195V but they have no obligation to do so. Effectively there is a loophole which the electricity suppliers have created.

As I have said I have written letters to 24/7 (EDF Energy), Energywatch, David Chare (Projects Office) with a full dossier of information. EDF Energy have responded again with a standard letter, to which I replied again stating further frustration and further information. Since they fail to respond directly to the low voltage situation that applies after a power-cut in Cambourne i.e. the 138V that has been measured. They still think this isn't possible. Hopefully we will get somewhere, although fingers and toes crossed.

In any case, Potterton in the end identified the root cause and are putting a fix in place moving forward although I just hope a further powercut doesn't result in a low voltage i.e 138V as more Cambourne residents may be effected. I hope EDF Energy and the Projects Office will work to make sure this is the case!!!

Cheers

Clayton