I have an electric shower which worked perfectly until my neighbours built an extension. Since then my water pressure is constantly fluctuating which has caused problems with the shower. The temperature of the water can be perfect initially but will suddenly change and I’ll either be almost scalded or be drenched in cold water. I know it isn’t the shower at fault because it works perfectly when the neighbours are away on holiday. I live in a semi-detached ex council property. However, it is not the neighbours I’m attached to that is causing the poblems. Any suggestions as to what if anything can be done?