Skip to Navigation Skip to Content
Main thumbnail

In order to work legally and safely, all gas operatives must:

  1. Have undertaken suitable ACS gas courses
  2. Hold a valid ACS certificate of competence
  3. Be registered with the Gas Safe Register.


What is ACS?

The Accredited Certification Scheme (ACS) is the industry recognised and accepted route for experienced gas operatives to gain the certificate of competence needed to become a member of the Gas Safe Register.

The scheme is overseen by the United Kingdom Accreditation Service (UKAS).


What does it cover?

The ACS qualification consists of CCN1, the core gas safety element which is compulsory and must be achieved before any further assessment can be undertaken.

There are further area specific gas safety elements for domestic NG, LPG, commercial heating, commercial catering, commercial laundry, emergency service provision and meter installation.

In addition, ACS covers all gas appliances; from central heating to cookers and gas fires.


Initial assessment

CCN1 assessment takes the form of practical tests and multiple choice question papers. Initial assessment covers:

  • Gas safety regulations and other relevant legislation
  • Combustion, relevant pressures and gas rates
  • Gas pipe work
  • Tightness testing and purging, including low and medium pressure
  • Chimney systems recognition and testing
  • Ventilation
  • Gas controls
  • Flue gas analysis

Alongside CCN1, operatives must take initial assessment in the appliances they will be working on.

Our CCN1 initial assessment course covers Central Heating Boilers & Water Heaters (CENWAT), Cookers (CKR1) and Space Heaters (HTR1).

There are a range of other appliance qualifications available.

The appliance part of ACS initial assessment, covers:

  • Installation
  • Commissioning
  • Servicing and maintenance
  • Basic gas safety fault finding


When do I need to reassess?

On passing the initial assessment, gas operatives will receive the ACS certificate of competence needed to join the Gas Safe Register – this is valid for five years.

Reassessment can take place any time in the six months prior to expiry.

Failure to hold current evidence of competence will result in suspension or removal from the Gas Safe Register, so it’s really important to keep your ACS qualifications up to date.


Is ACS for me?


To qualify for ACS assessment you must satisfy certain criteria.


Category 1 applicants are experienced gas engineers who already hold a relevant qualification.  They maybe renewing an existing ACS certificate or a certificate that has expired in the past 12 months, or seeking certification in a new area of work.

Click here for ACS initial

Click here for ACS re-assessment courses


Category 2 applicants can undertake ACS Assessment if they can demonstrate evidence of a recognised qualification in a trade associated with gas work, for example, plumbing, and that they have ‘on-the-job’ experience under direct supervision of a Gas Safe Registered and competent operative.

Click here for our entry-level gas course, for candidates with suitable experience.


Category 3 applicants are new entrants to the gas industry, and need further qualifications and/ or experience before they can undertake the ACS Assessment. ACS assessment would be part of a heating apprenticeship, for example.

Click here for our New Entrants gas course.


Gas Safe Register and the law


Registration with the Gas Safe Register is a legal requirement for anyone carrying out gas work in the United Kingdom, Isle of Man and Guernsey under the Gas Safety (Installation and Use) Regulations 1998.


Each registered engineer will be issued with a Gas Safe Register ID card which shows you are competent and safe to work with gas.


Play your part in spreading the Gas Safe message by proudly presenting your ID card at every opportunity, making sure your customers understand the Gas Safe Register brand is the only trusted, safe and legal organisation for trades’ people working with gas.


Enrol with Logic4training


Logic4training is a registered ACS Assessment Centre and we offer an extensive range of gas training courses and packages.  Whether you’re an experienced installer looking to renew your ACS qualification, or a new entrant wanting to become a Gas Safe Registered for the first time, we have a course for you:


If you would like more information please call 0208 845 7222

    Newsletter Sign Up

    For industry news, special offers and the latest from our centres, sign up to our mailing list

      Sign me up for the newsletter!