Daikin · Heat-pump or fixed-AC model
Altherma 3 H HT
Daikin Altherma 3 H HT is a current R32 high-temperature air-to-water family in 14, 16 and 18 kW capacity classes.
Specifications
| Specification | Value |
|---|---|
| Type | air-source, air-to-water high-temperature split system |
| Supply phases | single or three, depending on EPRA code |
| Rated output (kW) | 14, 16 or 18 capacity class |
| Maximum flow temperature (°C) | 70 at -15°C outdoor air by heat-pump operation, under the manufacturer's stated condition |
| Refrigerant | R32 in the outdoor circuit |
| Minimum operating temperature (°C) | -28 |
| Sound pressure at stated distance (dB) | 43 to 48 on current UK package pages |
| MCS certified | current exact EPRA14, EPRA16 and EPRA18 combinations were present on 23 July 2026 |
| Warranty (years) | 2 standard; extensions depend on registration, installer route, maintenance and terms |
Altherma 3 H HT is Daikin’s R32 high-temperature Altherma 3 family. Its EPRA outdoor-unit classes are 14, 16 and 18 kW, with single-phase and three-phase forms in the technical schedule.
HT identifies a specific outdoor range
HT should not be treated as a general label for every Altherma capable of serving radiators. The 14 to 18 kW EPRA schedule is different from the 8 to 12 kW Altherma 3 H MT range and from the newer R290 Altherma 4 H.
Daikin states that the H HT outdoor unit can deliver 70°C leaving water at -15°C outdoor air by heat-pump operation. It also states operation down to -28°C. The 70°C figure keeps both conditions attached; it is not a claim that every system output remains at its capacity name throughout the whole operating envelope.
F and W describe the indoor package
Altherma 3 H HT F has a floor-standing indoor unit with an integrated 180 or 230 litre hot-water cylinder. H HT W uses a wall-mounted hydraulic unit with separate hot-water storage where required. Heating-only and reversible indoor variants, backup-heater ratings and electrical supplies create further code differences.
Current UK package pages give outdoor sound-pressure ranges of 43 to 48 dB(A). A planning calculation needs the exact model’s sound-power declaration rather than substituting this package-level sound-pressure range.
Certification and warranty
Exact EPRA14, EPRA16 and EPRA18 combinations were current in the MCS (Microgeneration Certification Scheme) Product Directory on 23 July 2026. The applicable record includes indoor equipment, so the outdoor capacity alone is not the complete certified identity.
Daikin’s live UK warranty page stated a two-year standard term at the review date and described air-to-water extensions through Stand By Me. Registration, installer status, annual maintenance and the issued certificate determine the term for an individual system.
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.