Safe electrics: The hidden dangers 

With the growing prevalence and importance of electrics in modern gas boilers, electrical safety has become a hot topic in the heating industry. Neil Macdonald, technical manager at the HHIC, looks further at considerations that need to be made.

Modern gas boilers can be seen to be a gas appliance using electricity, or an electrical appliance burning gas. While it’s clear that it is the combustion of natural gas or LPG which allows the boiler to fulfi l its primary purpose, the lines are no doubt beginning to blur. With the often complex and highly technical array of components and functions, such as modulating fans and air-gas-ratio valves, electrics are playing an ever-increasingly dominant role in boiler functioning.


The publication of Gas Safe Register TB 118 covers the suggested knowledge, skills and competencies the modern gas engineer should hold, including competent safe electrical isolation and the use of electrical fault-fi nding equipment. Meaning skills and training are once again at the forefront.

Engineers take a variety of routes into the heating industry, some charting the formal apprenticeship route, whereby they may learn robust business procedures that their employer already has in place for safely working with heating systems and electrical appliances. For others though, especially where the focus has been on “gas safety”, it may have been left for them to pick up what they could from colleagues or mentors on the district, or perhaps, inadvisably where electrical safety is concerned, attempt some “self-learning”.


Providing a positive step forward was the launch of the Institution of Gas Engineers and Managers, IGEM, IG/1 document – standards of training in gas work – which specifi es minimum content and criteria for training courses designed to lead to initial ACS accreditation or equivalents. From the 1st of October 2018, anyone undertaking such assessments has needed to provide evidence that they have undertaken an IG/1 approved training course.

IG/1 includes high-level content which learners must be trained on, such as safe isolation, safe working procedures including overcurrent and shock protection from electrical circuits, basic electrical theory and the dangers of electrical equipment, earthing & bonding, among others.

This is hugely encouraging for the industry as it creates a clear driver for those offering quality, IG/1 authorised training in gas work, to ensure that learners are equipped with the knowledge and skills to work safely on gas appliances, equipment and electrical supplies.

At time of writing, it is also proposed that registered engineers undertaking reassessment in relevant work categories, self-declare that they have the competence to safely isolate 230v electrical equipment. This would undoubtedly be a small step in the right direction, perhaps driving some towards training, if not already competent, but HHIC member companies have openly wondered if this is sufficient? Should we do more? To ensure safety, and raise the bar in terms of industry competence, HHIC would have liked to have seen the potential for a practical assessment of competent safe electrical isolation fully explored, as a pre-requisite to ACS reassessment, recognising the strict “matters of gas safety” remit of ACS means it cannot currently be included within the assessment process itself.


Whatever the work task in hand, it is essential to remain vigilant, and using the appropriate test equipment and methods, prove beyond doubt that the equipment to be worked on is safely electrically isolated.

Safety is paramount when working with electrics, especially when you consider that the average human body can be said to have a typical electrical resistance of around 2500 Ohms in normal conditions, potentially much less if the person is wet, perspiring or if their skin is broken. Ohms Law therefore tells us that in the eventuality a person makes contact with a standard 230v live electrical conductor, the initial current drawn would be around 0.01 Amps.

This may not sound like much but consider that a standard heating system is fused at 3 Amps, it means the fuse wouldn’t ordinarily fail until this amperage was exceeded. This is important as an electrical current of only 0.1 Amps can be enough to stop a human heart. RCD protection of circuits will of course provide additional safeguarding but may not always be installed.

My advice: Consider training and safety, it could save your life.

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