I have an old Modena 80 E combi boiler that is randomly short cycling on windy days. The burner goes out and re-ignites within a few seconds and continues to burn for between five and forty seconds before stopping again. Under normal conditions the boiler works fine but as soon as it gusts over thirty miles an hour the cut-outs start and continue until the wind subsides. I had the boiler serviced but the gas engineer couldn't identify the problem and wondered if a good clean out of built up debris around the burner would rectify the problem. It didn't. He said there were no readings of fumes blowing back and that the flame pattern was good. I contacted another engineer who just says it could be tricky to pinpoint the cause. I wondered if the pilot light is being blown out causing a safety cut out and closing the gas supply down until the pilot re-ignites. If this is the case is it likely to be a dirty/faulty thermo couple issue or would it short cycle on windless days if this was the case?