I think i had a similar problem with one of these from new, it would run but when it reached temp it wasn't modulating, and there fore would cut out. you may find that there are two adjusters on the gas valve, one gives you your max burner pressure when required and the small screw in the middle gives you your min, if you adjust the min up a little bit you may find this solves it !!!!!!! ( mind you you should be corgi if you do touch it)
garry, December 2005
