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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This afternoon is going to remain cloudy with some heavy showers. Highs of 11 degrees C.
Emergency services workers and members of the public have been recognised for their actions during a fatal crush at a Northampton nightclub.
Ambulance crews in the region dealt with a record number of calls in January - but too many of them were for non-emergencies.