For a couple off days, we have been hearing a couple of very loud clunks coming form the boiler area, so last night i had a quick look and think that i have found the problem, It seems to be coming from the three way diverter valve, thats positioned under the boiler, and only when the HW is turned OFF. I will be calling the plumber that fitted it last year to take a look, but if you chaos have any ideas that would be great.............. the unit is a HONEYWELL SUNDIAL Y PLAN 3 position diverter valve, and i will put the pics up as soon as i can get onto the photbucket site and post em!!!!

