New Boilers on Old Heating Systems: Hydraulic Separation

This free online CPD course from BESA Academy is presented by Hamworthy Heating and explains how to correctly connect new boilers to existing heating systems using hydraulic separation. The course covers the differences between sealed and open vented heating systems and how to assess and choose the best method of separating the primary and secondary circuits.

This course is free of charge and CIBSE accredited for CPD. Download your certificate on completion.

What You Will Learn

This 35-minute course is delivered in two parts covering:

• Part 1: How to establish the existing system type and configuration
• Part 2: Primary circuit design and connecting to the secondary circuit
• The differences between sealed and open vented heating systems
• How to assess which method of hydraulic separation is appropriate
• The principles of primary and secondary circuit separation
• Best practices for connecting new boilers to old heating systems

Who Should Take This Course?

This course is suitable for heating engineers and installers replacing boilers on existing systems, building services designers and consultants involved in heating system upgrades, facilities and maintenance professionals managing boiler replacements, and anyone responsible for specifying or installing new boilers where hydraulic separation is required.

Why Hydraulic Separation Matters

When replacing boilers on older heating systems, simply connecting a new boiler directly to the existing pipework can cause flow and pressure problems, reduced efficiency, and premature boiler failure. Hydraulic separation ensures the primary circuit (the boiler side) and secondary circuit (the heating system side) operate independently, allowing each to function at its optimal flow rate and pressure.

Understanding how to assess the existing system and select the correct separation method is essential for successful boiler replacements on older installations.

The Benefits of This Course

Completing this course will help you:

• Understand the principles of hydraulic separation in heating systems
• Identify whether a system is sealed or open vented
• Select the appropriate method of separating primary and secondary circuits
• Design and install boiler connections that ensure reliable, efficient operation
• Avoid common problems caused by incorrect boiler connections
• Earn CIBSE-accredited CPD to support your professional development

Course Format

Duration: 35 minutes
Format: 100% online, self-paced
Structure: Two-part course
Assessment: Knowledge check questions at the end of the course
Certification: CPD certificate available to download on completion
Accreditation: CIBSE accredited
Cost: Free of charge

Frequently Asked Questions

What is hydraulic separation in heating systems?
Hydraulic separation is a method used to allow the primary circuit (the boiler side) and the secondary circuit (the heating distribution system) to operate independently. This ensures that each circuit maintains the correct flow rate and pressure without negatively affecting the other.

Why is hydraulic separation important when replacing boilers?
When a new boiler is installed on an existing heating system, mismatched flow rates and pressures can cause inefficiency, noise, or premature boiler failure. Hydraulic separation helps prevent these issues by allowing the boiler and heating system to operate under their optimal conditions.

What is the difference between sealed and open vented heating systems?
Sealed heating systems operate under pressure and are closed to the atmosphere, usually using expansion vessels. Open vented systems include a feed and expansion tank and are open to the atmosphere, allowing pressure changes to be managed through the tank.

Who should take this course?
This course is suitable for heating engineers, installers, building services designers, consultants, facilities managers, and maintenance professionals involved in boiler replacements or heating system upgrades.

What methods can be used to achieve hydraulic separation?
Common methods include the use of low-loss headers, hydraulic separators, plate heat exchangers, and buffer vessels. The correct method depends on the system design, flow requirements, and the condition of the existing heating network.

How long does the course take to complete?
The course takes approximately 35 minutes to complete and is delivered in two parts. It is fully online and self-paced, allowing you to complete the training when it suits your schedule.

Is the course accredited for CPD?
Yes. This course is accredited by CIBSE for continuing professional development (CPD), helping professionals maintain and demonstrate their technical knowledge.

Will I receive a certificate after completing the course?
Yes. After successfully completing the course and the knowledge check questions, you will be able to download a CPD certificate confirming your participation.