Hi Im losing pressure at the rate of about half a bar over two weeks and have to top the system back up to 1.5 bar. Assuming its a leak in the loop I discounted any leak upstairs as it would show through the plaster ceiling as a stain, and I have had the floorboards up underneath all the rads downstairs and they are bone dry.Could any of you experienced guys let me know 1. how much water that equates to over two weeks and 2. could I be losing it within the boiler condensation or steaming away etc. Yhe boiler is a worcester 24CDI