I had a similar problem and the boiler engineer had to replace the temperature probe n top up air pressure in the expansion vassel. He charged me £65. Hope this helps.
After the recent high profile events like 9/11 and many more, I find hard to believe any propaganda stories given by any one or that of in the past. They need to be investigated properly as we have technology and capability to bring all black and white to people rather than fooling them with...