I read extensivly on this forum to try and assertain what my boiler problem could be, but I am not certain and would like some advice. My boiler had been leaking for some time and I knew this was due to the condense trap but the the leakage began to increase and the pressure would constantly drop so I had a Gas engineer out and he opened the boiler and as we put on the centeral heating and watched it work for about five minuits it started to spert out watery steam from the bottom front part of the combustion chamber and heat exchanger he now tells me i need a new Heat exchanger. Is he correct of is it just a seal that has gone? thanks for your help.