HI, Had a new boiler installed a few months back ( Worchester greenstar 30i) ever since around the same time every morning we have a ticking noise for a min or two and then a thud (like something is closing) it happening more or less the same time every morning? (6.30am) and some times during the day, no one in the house is up, no toilets flushed etc, there are no timer set on the boiler and I have even turn the boiler off (via plug) the night before and it still happens? it only started happening once the new boiler was installed, I have turn the water off and drained all the water and refilled. any idea's? driving me crazy?