Would you ever use a boiler that's been labelled at risk? Had an annual service and discovered that the whole external part of the flue has been knocked off! Getting a quote for a new one and will have it fitted asap but in the mean time boiler has to be labelled as at risk due to the possibility of gases coming back in. No dangerous levels of carbon monoxide detected at present though. Gas man said it's up to me and he didn't actually turn it off although he ticked the form to say he had. I've since turned it off myself. Heating obviously not required just now anyway but it's annoying having no hot water. We must have been using it for weeks without realising, as I suspect it happened when next door had some building work done a month or 2 back. Wondering if it would be ok to turn it on just to run a bath occasionally then put it straight off, or should we just consider it out of use until properly fixed?