Unvented Hot Water Systems | Options Skills
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Unvented Hot Water Systems


For years, the UK has met hot water demand in a variety of ways. Many traditional installations continue to work in homes and offices to this day, from gas and oil to solid fuel and electricity. However, with the ever-evolving industry, there are more options than ever before.

Yet, renewable energy technology in the replacement market creates challenges, from the difficulties faced installing in existing premises and the ever-changing technology to understanding and utilising realistic energy-saving options and ensuring all technology is compliant.

This training program has been designed for plumbing and heating engineers to demonstrate understanding and competency in installing, servicing, and maintaining domestic hot water systems.

Assessment takes place through multiple-choice assessments, scenario questions and observed practical tasks.

We deliver training as part of our ACS Gas & Renewables Training Course. However, it can also be undertaken by existing gas and heating engineers as an add-on course.

Qualification renewal is required every five years.

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Unvented hot water systems (G3)

  • Regulations, standards and guidelines
  • Understanding of the storage, heating and expansion of hot water (HW)
  • Design and Installation considerations
  • Components and their functionality
  • System and safety controls
  • Maintenance and servicing of HW systems, including Unvented HWS
  • Health and safety considerations
  • Identifying different types of water heating appliances and methods of heating water.
  • requirements for accreditation and Competent
  • Introduction to unvented hot water systems and controls.
  • Direct and indirect unvented hot water systems, materials, sizes, and capacities.
  • Considerations for installation, commissioning and maintenance requirements, advantages and disadvantages, control, and safety.
  • System fault diagnosis.

This course will allow you to:

  • Extend your scope of knowledge and understanding of heating and hot water storage systems, ranging from sink heaters to unvented hot water systems.
  • Give you a working understanding of safely heating and storing hot water,
  • An insight into legionella control
  • A solid grounding for progressing to newer technologies (a prerequisite to heat pump courses).
  • Open up more revenue streams for your business.
Plumbing student connecting copper piping to a gas meter
Two students sat desks completing written study

Nationwide Job Opportunities

Major companies looking for our students.

Experience Needed

No qualifications or experience required.

Class Sizes

Limited class sizes for higher standard training.


Continued support after you've qualified.

Hidden Extras

Upfront about costs, no nasty surprises.

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We pride ourselves in offering a great service and training to our students. With that in mind we teamed up with FEEFO™ to collect impartial reviews with our trainees once they have finished their course. FEEFO™ is a leading review platform, offering an unbiased independent review platform to leading UK businesses.

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