A practical checklist for air-source and ground-source systems. This guide explains the decision points without promising that one answer fits every property.

Start with operating history

Changes in comfort, noise, electricity use or error codes direct the inspection.

For start with operating history, connect the explanation to pressures, strainers, temperatures, airflow, controls and fault history. The written scope should show the practical consequence for comfort, space, disruption, controls or cost, and identify any item that still needs confirmation. Pay particular attention to treating a design problem as routine maintenance or resetting evidence; this is where an apparently simple comparison can become misleading. Ask who owns the calculation, enabling work, commissioning and aftercare, then keep service readings, observations and prioritised recommendations so later adjustment or fault finding begins with evidence.

Check both sides of the system

The heat source, water circuit, strainers, pressures, temperatures, safety devices, controls and hot-water operation all contribute.

For check both sides of the system, connect the explanation to pressures, strainers, temperatures, airflow, controls and fault history. The written scope should show the practical consequence for comfort, space, disruption, controls or cost, and identify any item that still needs confirmation. Pay particular attention to treating a design problem as routine maintenance or resetting evidence; this is where an apparently simple comparison can become misleading. Ask who owns the calculation, enabling work, commissioning and aftercare, then keep service readings, observations and prioritised recommendations so later adjustment or fault finding begins with evidence.

Finish with useful evidence

A service should leave the homeowner with recorded findings and prioritised recommendations, not simply a ticked box.

For finish with useful evidence, connect the explanation to pressures, strainers, temperatures, airflow, controls and fault history. The written scope should show the practical consequence for comfort, space, disruption, controls or cost, and identify any item that still needs confirmation. Pay particular attention to treating a design problem as routine maintenance or resetting evidence; this is where an apparently simple comparison can become misleading. Ask who owns the calculation, enabling work, commissioning and aftercare, then keep service readings, observations and prioritised recommendations so later adjustment or fault finding begins with evidence.

The practical next step

Use the guidance in What should heat-pump servicing include? to ask better questions, then base the final decision on room-by-room heat loss, emitter output, site constraints and a written design. Renewable Heating Hampshire can help turn the general principle into a property-specific assessment.