Can you please help me. I have a British Gas Combi Boiler manufactured by Bosch. Model No. is ZWBR 11-37 ICC2. It was installed by British Gas on 1st May 2002 and has been maintained by British Gas since then. To start with we had fault code F7 when a red light flashes and the display asks to press reset button. British Gas engineer found no fault and we continued to reset the boiler. After that fault code A1 appeared and the boiler had no pressure thus no heating or hot water. This has happened couple of times. British Gas engineer changed some electrodes and this did not help. Water pressure continues to drop and the British Gas engieers have been coming and going but no one has yet found the exact problem. They think water is leaking under the floor but we can't find any wet or damp patch. There is no water out the over flow either. Last time the engineer came and told that they want shot the heating to see if the water leak is in the house or the boiler has problem. This is nearly after 3/4 months. We are old and infirm couple and can not live without heat or hot water. So I have to add water to the boiler almost very day. We have Home Care agreement with British Gas covering the central heating system, plumbing and electricity.