Answer first
Ask for the charging structure before the visit: call-out or diagnostic fee, included time, hourly labour, travel, VAT and how parts are authorised. A controls setting or blocked filter is a different job from a compressor, refrigerant or buried-pipe fault.
Preserve fault codes, photos and operating history. Do not repeatedly reset the system if the manufacturer warns against it, and do not open refrigerant or electrical components yourself. Better evidence can shorten diagnosis and avoid speculative part replacement.
A repair quote should follow evidence, not a guessed component
View sourceInstallation and product warranties can cover different parts of the job
View sourceKeep commissioning, fault and service records together
View sourceTell FLO the fault before you approve a repair
Share the property, postcode, current heating and the cost question you want answered. FLO will explain what can be estimated now and what needs a survey before a figure is reliable.
Separate appliance, hydraulic and control faults
A heat-pump alarm may be caused by the outdoor unit, a sensor, low water flow, a dirty strainer, a zone valve, system pressure, power supply or a control setting. Replacing parts before identifying the chain of evidence wastes money.
Give the engineer the exact code, when it occurs, recent changes and whether heating or hot water still works. Photographs of the controller and plant area can help allocate the right person.
Check every warranty route
Product warranty, installer workmanship cover and any consumer-code protection are separate. Confirm registration, service conditions and whether the proposed repair must be authorised by the manufacturer.
A warranty may supply a part but not every labour, access or consequential cost. Ask who is responsible before approving chargeable work.
Get an approval point
A good booking process states the initial diagnostic charge and asks for approval before expensive parts or additional hours are committed. The written diagnosis should identify confirmed findings and any remaining uncertainty.
Where a replacement is proposed, compare it with repair cost, age, remaining warranty, parts availability, likely efficiency and whether other system faults would remain.
Avoid false economies
Repeated resets, temporary boosts or topping pressure without finding the leak can mask a problem and increase cost. Unqualified refrigerant or electrical work can create safety and warranty issues.
For an urgent loss of heat, ask about safe temporary hot-water or heating arrangements while the proper part is sourced. A rushed irreversible replacement is not the only response to a winter fault.
What to read next
Related answers and services
Questions people also ask
Can a repair price be given from a fault code?+
Sometimes a likely range can be discussed, but a code often describes a condition rather than proving which component caused it.
Will a service fix the fault?+
Minor issues may be resolved, but a service and diagnostic repair are different scopes; disclose the fault when booking.
When is replacement better than repair?+
Consider age, warranty, repair total, parts availability, repeat faults, efficiency and whether the wider system still suits the property.
Evidence used for this answer
Figures are explained in context and links go to the independent source. Prices, tariffs, scheme rules and standards can change, so check the source again before making a financial or technical decision.
- MCS domestic heat-pump guideConsumer guidance covering design, installation, controls, handover and maintenance.
- Home Energy Scotland: heat pumpsCurrent Scottish guidance on typical costs, savings, lifespan, comfort and combining a heat pump with solar panels.
- Energy Saving Trust: heat-pump questions answeredIndependent answers on servicing, maintenance and common household heat-pump decisions, including a current typical service-cost guide.