losing pressure means you have a leak on the heating circuit, check around all visible pipework and radiators for signs of leaking, also check the relief pipe (usually outside below the flue). if you can't see any leaks then it's most likely under your floor. as far as not igniting goes check the insructions for error codes.
you can look at instructions online at http://www.partsarena.com/baxi/
it's under range powermax.
Ian, August 2009
