Potterton puma 80e ?

I am having the same problems as a few people on this site, my low water pressure light came on so i tried the recomended answers on here by disconnecting the yellow wires from the switch, and prestow the unit fired up, i purchased a new switch fitted it and it worked fine got all the air out of the system, it lasted about an Hour and the light came back on, i disconnected the yellow wires again and it worked, could this be a faulty switch or could theere be other problems.

Any help you can give will be much appreciated

Cheers mike

Mike Williams
November 2011