Losing pressure on Greenstar 30cdi boiler

Look outside, you will see a 15mm copper pipe attached to your boiler, this pipe is from the boiler pressure relief valve, there you will probably find it leaking, if so call your local Gas Safe engineer to make good repairs. Additional The plot thickens. If you are sure there is no definite signs of loss of heating system water above ground, then do you have any heating pipework that may run in a ground floor void and/or a solid concrete floor, as this may be the cause of the loss of water? Loss of water in a floor void obviously requires lifting up carpet and floor boards to make a thorough examination but loss of heating water in a concrete/solid floor is more difficult to detect unless there is evidence of damp patches within the solid floor. Good hunting

The loss of pressure could be from your system or the gas to water heat exchanger has pin holed and the water maybe going down the condense. Worcester do a 10 year warranty on this so call them. The water leak from the cold sounds like it's under a ground floor so would not show easily. easy way of finding if it's the hot or cold pipe is to isolate the cold supply to your boiler and check your water meter dial. if its still moving then it's the cold, if not then it's the hot.