Viessmann · Heat-pump or fixed-AC model
Vitocal 350-A
Vitocal 350-A is a documented high-temperature R407C air source heat-pump family for larger heat loads, with indoor and outdoor configurations; current UK new-supply status is unconfirmed.
Specifications
| Specification | Value |
|---|---|
| Type | high-temperature air-to-water heat pump, indoor or outdoor installation |
| Rated output (kW) | 10.6, 14.5 and 18.5 by exact type |
| Rated-output conditions | A2/W35 |
| Maximum flow temperature (°C) | 65, including at -10°C outdoor |
| Refrigerant | R407C |
| Warranty (years) | 2 standard; paid extension to 7 subject to terms |
| Types | 351.A10, 351.A14 and 351.A20 |
| COP A2 W35 | 3.6, 3.5 and 3.2 |
| Cascade | up to five units; up to 92.5kW |
| DHW cylinder | separate |
Vitocal 350-A is a documented high-temperature air-to-water heat-pump family for larger heat loads and modernisation projects. Its schedule covers indoor AWHI and outdoor AWHO configurations in three sizes. A separate cylinder is required for domestic hot water.
Sizes and performance
The three type sizes are 351.A10, A14 and A20. At A2/W35, their rated heating outputs are 10.6, 14.5 and 18.5 kW. Their coefficients of performance at that same point are 3.6, 3.5 and 3.2.
The maximum flow temperature is 65°C, including at outdoor temperatures down to -10°C according to the UK technology brochure. This operating envelope can support higher-temperature emitters, but actual emitter retention and seasonal performance depend on the heat-loss and system design.
Configuration
Indoor versions use site-installed air ducts to and from the heat pump. Outdoor versions put the full air-side unit outside. Their dimensions and weights differ, so AWHI and AWHO documents cannot be used interchangeably.
The refrigerant is R407C. The range uses enhanced vapour injection and an electronic expansion valve to reach its higher flow temperature. Its Vitotronic 200 control can manage up to five units in cascade, giving a stated maximum combined output of 92.5 kW.
Current position
Vitocal 350-A remains in Viessmann’s broad UK comparison page and warranty schedule, but it is absent from the main heat-pump product navigation. Those retained records support identification and warranty checking; they do not establish current new supply. Current UK availability is therefore unconfirmed.
Vitocal 350-A has a two-year standard warranty with a paid seven-year extension, subject to registration, servicing and the full terms. Retained warranty terms do not establish current new supply.
The full AWHI or AWHO type code is needed when checking manuals, refrigerant obligations, acoustic data or parts. The family name alone does not identify the installation arrangement.
Related entries
Brand
Reference type
Heat-pump or fixed-AC model
Last reviewed
31 Jul 2026
Current status
UK new-supply status is unconfirmed.