Domestic to Commercial Heating Changeover Course

Includes TCP1A, ICPN1, CIGA1, CORT1, CDGA1 – 5 Days
Accredited by LCL Awards – Delivered in Welwyn Garden City

This 5 day Domestic to Commercial Heating Changeover course is designed for qualified domestic gas engineers looking to expand into commercial heating work for the first time. Accredited by LCL Awards, the course provides full training and assessment across TCP1A, ICPN1, CIGA1, CORT1 and CDGA1 modules, enabling you to become Gas Safe registered for both domestic and commercial heating systems.

Delivered at our Welwyn Garden City training centre, this programme blends classroom learning with extensive practical work on live equipment, giving you the knowledge and skills to safely install, commission, service and maintain a wide range of commercial heating appliances.

To attend this full changeover course, you must:

• Hold a current Core Domestic Gas Safety (CCN1) qualification or equivalent.
• Be Gas Safe registered for domestic work.
• Have practical experience working with gas installations.
• Provide valid photographic ID (passport or driving licence).

This course is for engineers moving into the commercial sector for the first time. If you are already qualified in these modules and simply need to renew, we also offer a Re-assessment course. Please, contact our admin team to discuss booking a reassessment.

Assessment is carried out through:

• Practical observation – working on commercial appliances, pipework and testing procedures.
• Written and multiple-choice exams – covering theory, regulations, combustion and unsafe situations.
• Scenario-based exercises – applying knowledge to real-world commercial installations.

Successful completion of all elements is required to achieve certification.

During this course, you will complete full training and assessment across the following modules:

• TCP1A – Tightness testing and direct purging of pipework not exceeding 1m³.
• ICPN1 – Installation of first-fix commercial pipework.
• CIGA1 – Indirect fired commercial appliances.
• CDGA1 – Direct fired commercial appliances.
• CORT1 – Radiant tube and radiant plaque heaters.

Your training package includes:

• All course modules (TCP1A, ICPN1, CIGA1, CORT1 and CDGA1).
• Registration and certification fees with LCL Awards.
• Full access to appliances, test equipment and workshop facilities.
• Course handbook and training materials.
• Lunch and refreshments (tea, coffee and juice) each day at our Welwyn Garden City centre.

After completing this course and gaining Gas Safe registration for commercial heating, you can:

• Work legally on commercial heating appliances and pipework.
• Extend your qualifications further with specialist modules such as Commercial Catering (CCC1) or Commercial Laundry (CLE1).
• Broaden your client base to include facilities management companies, schools, hospitals, industrial plants and more.

Is the training practical or just theory?

It includes both: hands-on work in workshops or real appliance setups (installation, fault diagnosis, flue, ventilation etc.), plus theory/tests.

Will this course keep my domestic qualification live?

Yes. Because this is a changeover/reassessment package, your domestic core (CCN1) remains valid; you are extending your scope into commercial while maintaining the domestic qualification.

CODNCO1 is the bridge qualification that enables domestic gas engineers to expand into commercial work safely and legally, forming the foundation for all further commercial gas appliance modules. It provides domestic-qualified gas engineers with the knowledge and skills needed to safely work on commercial gas systems. It covers the differences between domestic and commercial environments and prepares candidates for associated appliance modules (CIGA1, CORT1, CDGA1, etc.).

The training explores the application of gas safety legislation, British Standards and industry codes of practice in commercial environments, while reinforcing combustion principles such as burner pressure, gas rates, and the impact of carbon monoxide and other by-products.

Candidates learn to recognise the key differences between domestic and commercial systems, including appliance design, installation standards, pipe sizing, and operating pressures.

The course also covers ventilation and flueing requirements for larger premises, from chimneys to mechanical extraction systems, and provides clear guidance on identifying and managing unsafe situations in line with industry procedures.

Practical training focuses on tightness testing, purging, and pressure testing of commercial pipework, alongside strength testing and system integrity checks. In addition, engineers are taught the correct emergency actions to take in the event of a gas escape or unsafe appliance, as well as how to commission, service, and carry out essential safety checks on commercial heating installations.