What is air source heat pump replacement?
Replacing an existing air source heat pump starts with finding out what the old system got right and what needs changing. A new outdoor unit may be able to use the cylinder and emitters already fitted, but compatibility and condition need checking before they are retained.
Signs you may need air source heat pump replacement
- Repeated breakdowns or unavailable parts make further repair difficult to justify.
- The existing unit cannot maintain comfortable room temperatures despite checks and adjustments.
- An extension or insulation project has changed the building’s heating demand.
- You want to compare a major repair with a new unit and a fresh warranty.
What the specialist checks and does
- Review fault history, electricity use and the original heat-loss design.
- Check cylinder coil, controls, water quality, pipe sizes and emitter suitability.
- Plan safe isolation, refrigerant handling where needed and removal of the old appliance.
- Adapt connections and supports, then test and recommission the complete system.
- Explain new controls and provide warranty and disposal records as applicable.
A retained cylinder needs a suitable heat-exchange coil, not just enough litres. A different refrigerant or manufacturer may change clearance requirements and control compatibility. The new unit’s ability to turn down at low demand matters alongside its maximum output, especially if the old appliance cycled frequently.
Before you ask for a quotation
Send the old make, model, age and service history, plus any repair quotation. Say whether rooms were ever comfortably heated and whether hot water was adequate. Mention additions to the house since the original installation and share commissioning records if you have them.
Indicative cost and time
The site’s UK guide is £5,500–£11,000. Before any funding. This assumes useful parts of the existing installation remain. A new cylinder, incompatible controls, crane access or major pipe changes can push the total above the range.
The indicative timeframe is 1–3 days. Confirm what this covers, availability and any separate equipment lead time with the firm.
Qualifications, funding and permissions
Planning rules vary between UK nations and depend on the property and proposed unit. Do not assume an existing heat pump position or a neighbour's installation gives permission for yours. Check siting, noise, listed-building restrictions and any freeholder consent before ordering. Building Regulations and any required electrical or unvented-cylinder certification must be dealt with separately; MCS certification alone is not a blanket building-control approval. Read the Planning Portal guidance for air source heat pumps in England and confirm the position for your UK nation and property.
Finishing the job and keeping records
Ask the quotation to identify retained parts, excluded faults and separate equipment and workmanship warranties. Agree removal and disposal, making good and expected downtime. Reusing a component should be a checked design decision rather than an unstated saving.
Frequently asked questions
Can I keep the existing cylinder?
It may be possible if its coil, capacity and condition suit the new heat pump. Ask the installer to confirm compatibility in writing rather than assume all cylinders are interchangeable.
Can I use the Boiler Upgrade Scheme for a replacement?
The scheme does not fund replacing an existing low-carbon heating system. Do not deduct a Boiler Upgrade Scheme grant from a heat-pump-to-heat-pump replacement budget.
Should I repair the old unit instead?
Compare the diagnosed fault, parts availability, repair warranty and likely remaining service life with the complete replacement cost. Age alone does not settle the decision.
Air Source Heat Pump Cost is a consumer matching service. One online enquiry can bring up to four quotations from independent local specialists, depending on the work, coverage and availability. We do not carry out the work or employ the specialists. Companies joining the network are asked to provide relevant insurance details and references.
Describe your heat pump enquiry to request quotations without an obligation to accept.