The loss of water pressure is a really good warning of some very common problems that occur with boilers. If the pressure is low it is fairly easy to remedy, and this can usually be done by the homeowner. The constant water pressure is crucial to the efficiency of a?boilers system. The pressure for the majority of modern combi boilers is kept by cold water coming from the water mains supply via a mechanism called the filling loop A few things can cause the pressure to fall. It could be a leak somewhere in the boilers system. Or, if the radiators were recently bled it may be that pressure was lost at that point. Croydon Plumbers are a fully qualified plumbing service. However, it may not be obvious that there is a problem until a visual check of the pressure gauge is made. Water leaks, for example, could be very small and be missed at first, then become a larger problem later. A system can be re-pressurise through the filling loop. A look at the boilers manual will state if it can be re-pressurised by the homeowner. Or you could employ a professional like a Croydon Plumber to do the job. To do this: Firstly, identify the filling loop and the pressure gauge. Make sure that the gauge can be seen while using the filling loop (1.5bar is a good pressure). This filling loop will use a silver flexible tube with two handles, for off, the handles will sit across the pipework. Slowly move them so they are sitting in line with the pipework. You will hear water running through into the boiler. Carefully monitor the pressure gauge reading as it climbs back up and into the green area or the 1.5 bar sector marked on the gauge. Once this is achieved you can return both handles back to their original positions.