Daikin · Heat-pump or fixed-AC model
Altherma 4 H
Daikin Altherma 4 H is a current R290 high-temperature air-to-water hydrosplit family with wall-mounted and integrated-cylinder indoor options.
Specifications
| Specification | Value |
|---|---|
| Type | air-source, air-to-water hydrosplit |
| Supply phases | single or three, depending on outdoor and backup-heater code |
| Rated output (kW) | EPSKS 4, 6 and 7 classes; EPSK 6, 8, 10, 12 and 14 classes appear in current records |
| Refrigerant | R290 in the outdoor unit |
| Domestic-hot-water temperature range (°C) | up to 65 on current UK package pages |
| Minimum operating temperature (°C) | -28 |
| Sound pressure at stated distance (dB) | down to 28 in the manufacturer's stated quiet operating condition |
| MCS certified | current exact EPSK and EPSKS combinations were present in the MCS directory on 23 July 2026 |
| Warranty (years) | 2 standard; current air-to-water routes describe 5 free after registration or a paid 7-year route, subject to terms |
Daikin Altherma 4 H is a current high-temperature air-to-water family using R290 refrigerant. It is a hydrosplit system: the refrigerant remains in the outdoor unit and water connects the outdoor and indoor equipment.
Outdoor and indoor codes both matter
Current technical and certification records use EPSKS for smaller outdoor units and EPSK for the wider capacity range. The published schedules include 4 to 14 kW capacity classes, with some overlap between outdoor-unit forms. Electrical supply also changes by code.
The H W package uses a compact wall-mounted indoor hydraulic unit and a separate cylinder or thermal store where hot water is required. H F uses a floor-standing indoor unit with an integrated hot-water cylinder. Indoor variants add backup-heater, reversible-operation and cylinder details, so Altherma 4 H 10 kW is not a complete system designation.
Temperature and sound figures have conditions
Daikin’s current UK package pages state operation down to -28°C and domestic hot water up to 65°C. They also advertise outdoor sound pressure down to 28 dB(A). That is a quiet-condition sound-pressure value rather than a family-wide sound-power figure for planning. An acoustic calculation needs the exact outdoor code and the manufacturer’s declared sound-power data for its operating mode.
The outdoor unit uses R290, so the manufacturer’s siting clearances and refrigerant safety zones form part of the installation design. They are not established by the indoor package name.
Certification and warranty
Exact EPSK and EPSKS combinations were current in the MCS Product Directory on 23 July 2026. The records pair outdoor and indoor equipment; the family name alone does not establish that an alternative combination has the same certification.
On the same date, Daikin’s UK warranty page stated two years as standard for residential products. Its air-to-water route described a free five-year term after Stand By Me registration and a paid seven-year option for qualifying installations, subject to maintenance and the full terms.
Related entries
Manufacturer and reference sources
Brand
Reference type
Heat-pump or fixed-AC model
Last reviewed
23 Jul 2026
Current status
Current in the manufacturer's UK range.