The Grant Aerona 290 is Grant UK's fifth-generation air-to-water monobloc using natural R290 propane refrigerant (GWP 3). Available in five capacities from 4 kW to 15.5 kW — select the output that matches your calculated heat loss on the variant selector. Every variant shares the same platform: DC twin-rotary compressor, electronic expansion valve, R290 leak sensor with independent ventilation channels, Quiet Mark accreditation across the range, powder-coated black casing, MCS certification, BUS grant eligibility, and up to 7 years guarantee when installed by a Grant G1 installer.

4–15.5 kW

Output range

R290

GWP 3 propane

A+++

ErP rating

-25 to +35°C

Operating envelope

Quiet Mark

Full range

Up to 7 yrs

G1 guarantee

BUS grant eligible

Every Aerona 290 model is MCS accredited and eligible for the UK Boiler Upgrade Scheme grant when installed by an MCS-certified installer in an eligible property. The whole range is also Connect & Notify approved.

R290 outdoor unit siting

R290 is an A3 flammable refrigerant. UK installation requires minimum clearances from doors, windows, drains and ignition sources per Grant's technical manual. The unit's refrigerant leak sensor and independent ventilation channels mitigate risk, but siting must still be designed correctly — most domestic gardens accommodate the unit easily; constrained sites need design review.

MCS + G1 installer required for grant and 7-year guarantee

To claim the Boiler Upgrade Scheme grant the installer must be MCS-certified. To unlock the 7-year Grant guarantee, the installer must also hold Grant G1 accreditation (completed Grant heat pump training). Quality Heating can connect you with MCS + G1 installers.

Glycol antifreeze is not permitted — use mechanical anti-freeze valves

Per Grant's installation manual, glycol antifreeze cannot be used in Aerona 290 primary circuits. External pipework must be protected using mechanical anti-freeze valves — the Aerona 290 has its own anti-freeze heater on the plate heat exchanger and heated base tray for the unit itself. Getting this wrong risks freeze damage and voids warranty.

Choose your capacity

Heating output	Grant model code	Cabinet family	Typical property fit
4 kW	HPR2904	Small (shared 4/6.5)	Small, well-insulated 1–2 bedroom homes and flats
6.5 kW	HPR29065	Small (shared 4/6.5)	Typical 2–3 bedroom UK homes
9 kW	HPR2909	Large (shared 9/12/15.5)	3–4 bedroom semis and detached homes
12 kW	HPR29012	Large (shared 9/12/15.5)	Larger 4-bedroom detached properties
15.5 kW	HPR290155	Large (shared 9/12/15.5)	Very large detached, older retrofits, or high-heat-loss properties

Two cabinet families across the range

The Aerona 290 uses two chassis sizes: 4 kW and 6.5 kW share a smaller cabinet; 9 kW, 12 kW and 15.5 kW share a larger cabinet. Grant publish separate UKCA safety declarations for each family. This matters when planning siting — confirm outdoor footprint against the specific model dimensions in Grant's installation manual.

Sizing tip

Every Aerona 290 is rated at -5°C air / 55°C flow — Grant's published outputs use this condition. In milder ambients the delivered capacity increases; at deeper ambients (down to -25°C) the unit continues to operate but at reduced output. Always size from a heat loss survey against your local design temperature.

Why choose the Aerona 290

R290 refrigerant — GWP 3

Natural propane refrigerant with a GWP of just 3 — close to one-thousand times lower than legacy split heat pump refrigerants. The most future-proof choice ahead of tightening UK F-Gas regulation.

Operates -25°C to +35°C

Reliable operation across the UK winter envelope down to -25°C ambient — dependable heat delivery through cold snaps without leaning on backup electric.

A+++ ErP rating

Top-tier seasonal efficiency label at 35°C flow — excellent SCOPs across every capacity in the range.

Quiet Mark across the range

Every Aerona 290 carries a Quiet Mark accreditation — not just selected models — thanks to acoustic cotton sound insulation in the casing and twin eccentric cam levers with balancing weights.

R290 safety built-in

Refrigerant leak sensor plus independent ventilation channels designed into the unit — engineered from the ground up around A3 refrigerant handling.

Electronic expansion valve + 4-way defrost

EEV precisely modulates refrigerant flow into the evaporator; the 4-way valve reverses cycle for efficient defrost. Result: tighter capacity control and quicker recovery from defrost.

Anti-freeze heater on HX and base tray

Plate heat exchanger and base tray both have integrated anti-freeze heaters — protects the unit itself; external pipework needs mechanical anti-freeze valves (glycol not permitted).

Powder-coated black finish

Durable powder-coated black casing — sleek modern styling and long-lasting outdoor finish.

Platform specification (all variants)

Range	Grant Aerona 290
Type	R290 monobloc air source heat pump
Available capacities	4 kW / 6.5 kW / 9 kW / 12 kW / 15.5 kW
Model codes	HPR2904 / HPR29065 / HPR2909 / HPR29012 / HPR290155
Refrigerant	R290 propane (GWP 3)
Compressor	DC twin-rotary, inverter-driven
Expansion valve	Electronic (EEV)
Defrost	4-way reversing valve
Circulating pump	Built-in PWM
Rating condition	-5°C air / 55°C water flow
Operating ambient envelope	-25°C to +35°C
ErP energy label	A+++ (at 35°C flow)
Electrical supply	230V, 50Hz, single-phase (all variants)
Certifications	MCS certified, BUS grant eligible, Connect & Notify
Acoustic	Quiet Mark (full range)
Safety	Refrigerant leak sensor, independent ventilation channels
Anti-freeze	Plate heat exchanger heater + heated base tray (glycol NOT permitted in primary; use mechanical anti-freeze valves)
Cabinet family	Small (4/6.5 kW) or Large (9/12/15.5 kW)
Finish	Powder-coated black
Guarantee	Up to 7 years parts and labour (G1 installer required)

What's in the box (every variant)

Grant Aerona 290 outdoor monobloc unit (capacity per selected variant)
Three condensate drain elbows
Three cable glands
Six crimp ring terminal fittings
ErP energy label
R290 installation & user instructions (Grant DOC 0204)
Base hole blanking plugs (9/12/15.5 kW only — six per unit)

What you'll also need (sold separately)

Grant Aerona Smart Controller (Standard or PP-cylinder variant — see our Grant accessory listings)
Grant Aerona Smart WiFi Hub for app-based remote access
DHW cylinder (heat-pump-suitable, indirect coil sized for low flow temperature)
Optional wall bracket kit (see Grant Wall Bracket accessory listing)
Mechanical anti-freeze valves on primary flow and return (glycol not permitted)
Grant Aerona 290 Flexi Hose & Valve Kit (Standard 28 mm or Primary Pro Insulated 28 mm)
Magnetic system filter on the primary return
Grant Aerona Installation Pack (Pack P / Q / R depending on system topology)

Frequently Asked Questions

Which kW should I choose?

Choose the variant that matches your calculated heat loss against your local winter design temperature. As a rough guide: 4 kW for small well-insulated 1–2 bed homes; 6.5 kW for typical 2–3 bed homes; 9 kW for 3–4 bed semis and detached; 12 kW for larger 4-bed detached; 15.5 kW for very large or lightly-insulated properties. Always confirm with a heat loss survey.

Is R290 safe for a domestic installation?

Yes. R290 is used across Europe in domestic heat pumps and refrigeration. The Aerona 290 is engineered around R290 safety with a refrigerant leak sensor and independent ventilation channels. The refrigerant is sealed inside the outdoor unit, which sits outside the property. UK installation rules govern minimum siting clearances to ensure safety; a competent designer will ensure these are met.

Why can't I use glycol antifreeze?

Grant's Aerona 290 installation manual specifically does not permit glycol in the primary circuit. Use mechanical anti-freeze valves on flow and return instead. The unit itself has a plate heat exchanger anti-freeze heater and a heated base tray; external pipework relies on mechanical valve protection.

Will my existing radiators work?

In most retrofit cases, yes — R290's higher flow temperature envelope covers typical UK radiator sizing. A heat loss survey identifies any coldest-rooms exceptions before commissioning.

Do I need to be MCS-registered to install this?

The unit can be installed by any competent heating engineer, but to claim the Boiler Upgrade Scheme grant the install must be by an MCS-certified installer, and to unlock the 7-year guarantee the installer must additionally hold Grant G1 accreditation. Quality Heating can connect you with MCS + G1 installers.

Do I need a separate controller?

Yes — the Aerona 290 requires the Grant Aerona Smart Controller (sold separately, in either Standard or PP-cylinder variant). Add the Aerona Smart WiFi Hub for app-based remote access.