Inspect, service and maintain heat pump installations _non-refrigerant circuits_
This subtopic focuses on the systematic inspection, routine servicing, and maintenance of the non-refrigerant components of air source and ground source heat pump installations. It covers the identification, diagnosis, and rectification of faults within hydraulic, electrical, and control circuits, ensuring safe and efficient system operation without handling refrigerant. Learners develop practical skills in using diagnostic tools and following manufacturer procedures to maintain system performance and compliance.
Assessment criteria
Topic Overview
The City & Guilds Level 3 Award in the Installation and Maintenance of Heat Pump Systems (Non-refrigerant Circuits) is a specialised qualification for experienced heating and plumbing professionals. It focuses on the non-refrigerant aspects of heat pump systems, including the design, installation, commissioning, and maintenance of the water and air circuits that connect the heat pump to the building's heating and hot water systems. This qualification is essential for those looking to expand their skills into renewable heating technologies, as heat pumps are a key component of the UK's strategy to decarbonise heating.
The course covers the principles of heat pump operation, system design considerations, and the practical skills needed to install and maintain heat pump systems safely and efficiently. It emphasises the importance of correct sizing, pipework configuration, and controls integration to ensure optimal performance and energy efficiency. Understanding these non-refrigerant circuits is critical because they directly affect the heat pump's ability to transfer heat effectively and reliably. This qualification is part of the wider Construction & Building Services sector, aligning with the growing demand for low-carbon heating solutions and the UK's net-zero targets.
Key Concepts
Core ideas you must understand for this topic
- →Heat pump system types: air source, ground source, and water source – understanding their operating principles and typical applications.
- →Non-refrigerant circuits: primary (source side) and secondary (load side) water circuits, including pipework, pumps, valves, and expansion vessels.
- →System design: calculating heat loss, selecting appropriate heat pump size, and designing pipework to minimise pressure drop and ensure correct flow rates.
- →Controls and integration: thermostats, weather compensation, blending valves, and how they interact with the heat pump to maintain efficiency.
- →Commissioning and maintenance: procedures for filling, venting, flushing, and testing the system, plus routine checks on filters, pumps, and pressure.
Learning Objectives
What you need to know and understand
- Perform a comprehensive visual and functional inspection of non-refrigerant heat pump components.
- Carry out routine maintenance tasks on air source heat pump hydronic and electrical circuits following manufacturer schedules.
- Diagnose common non-refrigerant faults in ground source heat pump installations using appropriate test instruments.
- Rectify identified hydraulic or electrical faults safely and in accordance with technical specifications.
- Evaluate system performance data to confirm correct operation after maintenance or repair.
- Complete accurate service records and communicate findings to relevant stakeholders.
Assessment Criteria
Key criteria assessors look for in your portfolio
- Award credit for correctly demonstrating safe isolation of electrical supplies before any service work.
- Award credit for systematic checking of water circuit components such as pumps, strainers, and expansion vessels.
- Award credit for accurately measuring and interpreting control voltages using a multimeter.
- Award credit for identifying and clearing fault codes by following manufacturer troubleshooting guides.
- Award credit for verifying system flow rates and temperature differentials against design parameters.
Assessment Guidance
Guidance for achieving higher grades
- 💡Always follow a logical diagnostic sequence: verify power supply, then controls, then mechanical components.
- 💡Reference the specific manufacturer's service manual provided during assessment; do not rely on generic knowledge.
- 💡Clearly label all connections and components before disassembly to ensure correct reassembly.
- 💡Use the commissioning checklist as a baseline when evaluating post-service performance.
- 💡Always refer to current regulations (e.g., Building Regulations Part L, MCS standards) in your answers – showing awareness of compliance gains marks.
- 💡When describing installation procedures, include specific details like correct pipe insulation thickness (to prevent heat loss) and the need for a buffer tank in certain systems.
- 💡For maintenance questions, mention the importance of checking system pressure, cleaning filters, and verifying that the heat pump is operating within its design parameters – practical knowledge scores highly.
Common Mistakes
Common errors to avoid in your coursework
- Neglecting to check for trapped air in hydronic circuits, which can cause circulation problems.
- Confusing similar fault codes between different heat pump manufacturers without consulting the manual.
- Overlooking simple issues like tripped breakers or blown fuses before assuming control board failure.
- Incorrectly adjusting flow rates or pressure settings, leading to reduced system efficiency.
- Misconception: Heat pumps work like boilers and can be installed with the same pipework. Correction: Heat pumps operate at lower flow temperatures (typically 35-45°C) and require larger radiators or underfloor heating, plus correctly sized pipework to avoid high pressure drops.
- Misconception: The refrigerant circuit is the most important part; the water circuit is simple. Correction: The non-refrigerant circuit is equally critical – incorrect design (e.g., undersized pipes, wrong pump) can cause poor performance, short cycling, or system failure.
- Misconception: Any heating engineer can install a heat pump without additional training. Correction: This qualification is specifically for experienced professionals because heat pump systems require different design principles, such as low-temperature operation and careful hydraulic balancing.
Frequently Asked Questions
Common questions students ask about this topic
Pass / Merit / Distinction Evidence Checklist
How your portfolio evidence is graded for CITY AND GUILDS OF LONDON INSTITUTE Inspect, service and maintain heat pump installations _non-refrigerant circuits_
Every vocational unit is marked against named criteria rather than an exam percentage. Your tutor's brief lists the exact codes for this unit — here is what each band is asking you to do.
Demonstrate baseline knowledge, accurate terminology, and core practical application.
Provide detailed analysis, structured explanations, and clear workplace reasoning.
Deliver thorough evaluation, original problem solving, and fully justified recommendations.
Before You Start
Prior knowledge that will help with this topic
- •Level 2 or 3 qualification in plumbing and heating (e.g., City & Guilds Level 3 Diploma in Plumbing and Domestic Heating).
- •Understanding of central heating system components (boilers, radiators, pipework, pumps) and basic thermodynamics.
- •Familiarity with electrical principles and wiring (e.g., controls, pumps, thermostats) as heat pump systems involve electrical connections.
Coursework AI Review
Paste your assignment brief and check your draft against its P/M/D criteria
Key Terminology
Essential terms to know
- System safety and isolation procedures
- Hydronic circuit inspection and maintenance
- Electrical and control system diagnostics
- Fault finding and rectification strategies
- Performance verification and reporting
Ready to learn?
AI-powered learning tailored to this unit