Figures obtained by ITV Anglia show hundreds of gas appliances have been worked on by unregistered engineers here in the East of England.
Nearly 250 jobs were carried out by unqualified engineers over the past two and a half years.
Nearly one in five of those were so dangerous the appliances had to be disconnected immediately.
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After what's been the hottest day in the region for almost 10 years there are warnings tonight about the dangers of swimming in open water.
Today was the hottest day of the year so far but temperatures will be down a little tomorrow with the risk of thunder.
A sizzling day for the Anglia region with temperatures rocketing into the mid 30's.