https://click4r.com/posts/g/18....784425/15-reasons-yo
Why It Is Important To Have An Annual Gas Safety Check Gas Safe engineers must inspect gas appliances and flues every year. This includes appliances that are shared, like boilers. During the inspection, the engineer will examine the flue. If needed, he may disassemble it. He will also check for carbon monoxide levels in each appliance. The engineer will disconnect the appliance if it's deemed "Immediately Dangerous". This needs to be resolved before the appliance can be used again