The hydrobox is a wall-mounted cabinet roughly the size of a boiler, or it can be built into a combined cylinder unit. It holds the heat exchanger, circulating pump, valves and controls. Outdoor units for split systems can be more compact than monobloc units of similar output, which helps where outdoor space is limited.
Installers covering Argyll and Bute keep refrigerant routes neat and protected along the outside wall. In Argyll and Bute homes where the clearest unit position is away from the plant cupboard, a split system allows a longer route indoors. Owners across Argyll and Bute can compare split and monobloc designs side by side at a survey in Argyll and Bute.
Who it suits
- Owners who would rather not use glycol or anti-freeze valves
- Exposed or frost-prone sites where outdoor water pipes would be a risk
- Houses with indoor wall space for a boiler-sized hydrobox
- Small yards, roofs or balconies that suit a more compact outdoor unit
Grants and rules for heat pumps in Scotland
The Boiler Upgrade Scheme does not apply in Scotland. Instead, homeowners in Argyll and Bute can apply to Home Energy Scotland for a grant of up to £7,500 towards a heat pump, with up to £1,500 more for eligible rural and island homes, plus an optional interest-free loan of up to £7,500. You need a written funding offer before any work starts.
There is no VAT on installing a heat pump anywhere in the UK, Scotland included, until 31 March 2027. Scottish permitted development rules and building standards apply, and the surveyor checks the unit position and any listed or conservation-area constraints.
Split system heat pumps prices in Argyll and Bute
The ranges below are typical installed prices for homes in Argyll and Bute, including VAT. A survey sets the exact figure, because two similar-looking houses in Argyll and Bute can need quite different radiators and pipework.
| Home | Typical size | Installed guide price |
|---|---|---|
| 1–2 bedroom flat or small terrace | 4–5 kW | £10,250–£13,500 |
| 2–3 bedroom terrace or semi | 5–7 kW | £11,350–£14,600 |
| 3 bedroom semi or small detached | 6–9 kW | £12,950–£16,750 |
| 4 bedroom detached | 8–12 kW | £15,100–£19,450 |
| 5+ bedroom or larger older house | 11–16 kW | £17,800–£24,300 |
Installed, inc VAT: unit, cylinder, controls, minor pipework and commissioning. In Scotland, Home Energy Scotland grants of up to £7,500 and interest-free loans may reduce the cost.
Towns we cover in Argyll and Bute
We cover 6 towns in Argyll and Bute for split system heat pumps. Each links to local guide prices and the grant position for Scotland.
| Town | Postcode district | Nearest town | Midwinter daylight |
|---|---|---|---|
| Campbeltown | PA28 | Girvan | 7 h 04 min |
| Dunoon | PA23 | Gourock | 6 h 57 min |
| Helensburgh | G84 | Greenock | 6 h 57 min |
| Lochgilphead | PA31 | Dunoon | 6 h 56 min |
| Oban | PA34 | Lochgilphead | 6 h 51 min |
| Rothesay | PA20 | – | 6 h 59 min |
Split system heat pumps questions
Do I need an F-gas engineer for a split heat pump?
Yes. Split systems usually use a fluorinated refrigerant such as R32, so installing, servicing or repairing the refrigerant circuit must by law be done by an F-gas certified engineer. That covers joining the refrigerant pipes, testing them for leaks and charging the system. Your quote sets out who carries out each part of the installation, including the refrigerant work.
Can a split system replace my combi boiler?
Yes, but like any air-to-water heat pump it needs a hot water cylinder, because it does not heat water instantly. The hydrobox can sometimes go where the combi was, with the cylinder in a cupboard, utility room or garage. Integrated units combining both are useful where one larger space is available. The survey checks what fits before the design is finalised.
How far apart can the outdoor unit and hydrobox be?
It depends on the model: each manufacturer sets a maximum refrigerant pipe length and height difference, and longer runs may need extra refrigerant. In practice a split system allows more flexibility than a monobloc's water pipes, so the outdoor unit can often sit on the far side of a house, on a flat roof or round a corner. The survey measures the actual route.
Is a split system more efficient than a monobloc?
Not inherently. Efficiency depends far more on design, meaning correct sizing, low flow temperatures and good controls, than on whether the unit is split or monobloc. A split system can avoid the heat loss and glycol of a long outdoor water run, which helps in certain layouts. The survey estimates seasonal efficiency for the specific units proposed, so you can compare like for like.