Hey there Frosty, We recenty had John Morgan out to have a look at our system and he recommended that we remove the diodes from the panels - they were installed according to the saftey regulations of the time, however those regulations have since changed. The diodes are prone to burning out - which two of ours had. Once we removed them the capability of the system improved as a pair of panels were not operating at all! How old is your system? Do you know if you have these diodes? Perhaps you could look into this with your system? Good luck. Cheers, Fran.