what is my problem with boiler?

I had a similar problem and got an engineer out. He didn't know what it was and put in a new circuit board. I paid £289 and still didn't have hot water. I couldn't get hold of him again. Then another engineer looked at it and all it needed was a new rubber diaphragm (costing pennies). he charged me £65 pounds having spent three hours on it!!
Hope this helps.

Hot chick
January 2009