Domestic to Commercial Gas Safety (CoDNC01)

This NICEIC-certified domestic to commercial gas safety conversion course is a combination of theory and practical assessment.

Who is this for?

The domestic gas installer who wants to convert their Domestic Core Gas qualification (CCN1)  to Commercial Core COCN1). Many of the elements from the domestic core course would have already been covered in CCN1 assessment, therefore it is not always necessary to undertake the complete core course for a specific range of appliances as a changeover assessment can be obtained.  

Entry requirements

  • This course can only be completed by operatives holding a valid CCN1 or COCN1 qualification
  • CoDNC01 re-assessment can take place up to 6 months before the expiry date. It must take place within the 12 months following the expiry date. It is illegal to install gas appliances without a valid qualification
  • Any operative undertaking gas assessment for the first time must complete a training programme

Course outcome

Once you have completed the assessment, this provides you with the core qualification to progress onto the appliance modules for commercial gas.

Course duration

3 days.



  • Candidates can undertake re-assessment of any element up to 6 months early without losing any time.
  • Candidates must produce any previous certificates as demonstrable evidence prior to reassessment.
  • All candidates who wish to undertake gas training and or assessment must produce evidence of their qualifications and meet required category 1 or 2 or meet the following criteria:
  • Category 1 candidate is someone who is a fully experienced gas operative possessing a gas fitting qualification or certificates of gas safety competence.Category 2 candidate is someone who is:
    • already involved in a trade associated with gas work, e.g. plumbing
    • who holds a nationally recognised qualification e.g. NVQ or City & Guilds craft certificate for the associated trade association