Reality Check · August 2026
Air Source Heat Pump Cost 2026: Online Kit Prices vs Full Installed Reality in Devon & Cornwall
What the online kit prices actually cover, and what a full MCS-installed system costs on older South West properties.
Quick Answer
Online kits look attractive, and for the equipment they are. A 6 kW Grant Aerona3 with cylinder and install pack is currently about £6,600. A 10 kW sits around £8,200, a 13 kW about £9,000 and a 17 kW just over £10,000.
A full MCS-installed system for most homes in Devon and Cornwall still comes in between £11,000 and £18,000 before the BUS grant, depending on size and the work needed. The difference is the design, the labour, the electrics, the commissioning and the work that turns a kit into a system that actually suits an older South West house. That is the figure the calculator uses, because it is the one that tends to survive a proper survey.
What the online prices actually buy
These are current public prices for complete kits with pre-plumbed cylinder and install pack (August 2026):
| Capacity | Public kit price (inc VAT) | What is included |
|---|---|---|
| 6 kW | £6,617 | Unit + pre-plumbed cylinder + install pack |
| 10 kW | £8,196 | Unit + pre-plumbed cylinder + install pack |
| 13 kW | £9,060 | Unit + pre-plumbed cylinder + install pack |
| 17 kW | £10,157 | Unit + pre-plumbed cylinder + install pack |
Unit-only prices start lower. These packs usually cover the outdoor unit, cylinder, volumiser or low-loss header, filter, feet, isolators and basic materials.
They do not include design for your house, labour, electrical work, MCS registration or any radiator changes.
What a full MCS install includes
- Heat-loss assessment and system design for the actual property
- Outdoor unit and correctly sized cylinder
- Buffer or low-loss header where needed
- Pipework, isolation and filtration
- Electrical supply, isolation and any upgrades
- Labour for installation
- Commissioning and MCS certificate
- The paperwork that unlocks the BUS grant
Radiator upgrades are shown separately when they are required.
Side-by-side (gross before grant)
Using the capacity bands in our calculator:
| Size band | Typical public kit | Our full installed band | Typical gap |
|---|---|---|---|
| 5–7 kW | £6,600–£7,500 | £11,000–£13,500 | £4,500–£6,900 |
| 8–11 kW | £8,000–£9,000 | £12,000–£15,500 | £4,000–£7,500 |
| 12–16 kW | £9,000–£10,200 | £14,000–£18,000 | £5,000–£8,000 |
Our bands already start from these public kit prices and then add the professional layer. Radiator work sits on top when needed: few or suitable emitters £0, many +£750–£1,250, full +£1,500–£2,500.
Where the extra money goes
Most of it is labour and time on site. On older properties you often need more pipework, better access or longer commissioning. The calculator builds that in so the figure does not fall apart later.
- Design and heat-loss calculation for the actual house
- Labour (typically 2–4 days depending on complexity and access)
- Electrical isolation, supply upgrades and any DNO notification
- Pipework adaptations (common with microbore in older South West homes)
- MCS registration, commissioning and performance certification
- Warranty activation that only applies with an MCS install
BUS grant reality
You can only claim the £7,500 (or the £9,000 uplift for eligible oil and LPG homes with no mains gas) through an MCS-certified installer. Buying the kit yourself does not unlock the grant. The installer still has to design, install and commission the system to MCS standards.
How the calculator treats these numbers
It starts with the public equipment prices and then adds the real cost of getting the job done properly in Devon and Cornwall. That is why the bands sit where they do. Online kit prices are useful for understanding the hardware slice. They are not the installed cost.
Want a planning band for your own home?
The free heat pump Passport already uses the full installed picture rather than the kit-only price. It is built for the kinds of older properties common across Devon and Cornwall. No obligation. Every submission is personally reviewed.
Get a realistic planning band →Frequently asked questions
Can I claim the £7,500 BUS grant if I buy the kit online?
No. The grant is only available when an MCS-certified installer designs, installs and commissions the system.
Why is there a gap between kit price and installer quote?
The kit is only the equipment and basic materials. The quote includes design, labour, electrics, commissioning, MCS paperwork and the work needed on your specific property.
Do I always need new radiators?
Not always. Many homes need only a few upgrades or none at all if the existing emitters are already suitably sized for lower flow temperatures. The calculator shows the uplift only when it is likely to be required.
Is the calculator figure a fixed quote?
No. It is a realistic planning band based on current public equipment prices and typical South West installation costs. A proper survey will refine it for your house.