This fire was fitted 5 years ago to an open flue with a normal chimney pot, it is very rarely used. (top up heating on very cold days) I doubt it gets more than ten hours use annually. The flue was swept before it was fitted, and has been swept and smoke tested since (it was clean). The problem is that after about 20-30 minutes running the noise of the fire changes, and it has "lit back" underneath the burner. It was serviced about 18 months ago, and this cured the problem, only to have me turn it on for the first time in ages, to find it did it again. My question is, what causes this to happen? is it poor design ( I am an engineer and I must say that when I watched my local corgi service the burner I was not impressed with the quality of construction or materials) Is it caused by the fire hardly ever being used? Has some dust or vermiculite found it's way into the injector elbow. Anyone heard about multiple problems of this type on this model Any ideas for a permanent cure to this problem greatly appreciated!
phil
phil