TonyMitchell
I understand that the regulator puts the six month time limit on voltage complaints, if the DNO does not fix out of tolerance voltages in that time they can be penalised.
I havent checked this recently but a couple of years ago I got involved with a farmer, his wind turbine would not generate as the farm voltage was too high so he was loosing revenue. I got the customer to send a registered letter and the issue was resolved by adjusting the taps on the transformer. The time limit is more relevant for low voltage complaints as the DNO may have to invest time and money upgrading plant. I know of customers fed by a bit of wet string who have argued for years with the DNO.