Worcester Bosch · Heat-pump or fixed-AC model
Compress 5800i AW
Worcester Bosch Compress 5800i AW is a current R290 air-to-water monobloc system offered with 4, 5 and 7 kW outdoor units.
Specifications
| Specification | Value |
|---|---|
| Type | air-source, air-to-water monobloc outdoor unit with several indoor arrangements |
| Rated output (kW) | 4.31, 6.43 and 7.09, by outdoor unit |
| Rated-output conditions | A2/W35 in 4, 5 and 7 kW capacity-name order |
| SCOP (seasonal coefficient of performance) at 35°C | 4.53, 4.53 and 4.54 in capacity order in the MCS directory on 23 July 2026 |
| SCOP at 55°C | 3.03, 3.28 and 3.29 in the same order |
| Maximum flow temperature (°C) | 75 |
| Refrigerant | R290, GWP 3 |
| Sound power (dB) | 40 at 4 kW; 42 at 5 and 7 kW |
| MCS certified | yes; MCS HP0329/05–15 across outdoor-only and specified indoor combinations, with no end date shown at review |
| Warranty (years) | minimum 2 under current terms; up to 7 appears in manufacturer material subject to training and terms |
| Capacity classes (kW) | 4, 5 and 7 |
| Supply phases | single |
| Dimensions, height × width × depth (mm) | 800 × 1100 × 540 outdoor unit |
| Weight (kg) | 143 |
Compress 5800i AW is Worcester Bosch’s current R290 air-to-water monobloc system. Its outdoor-unit capacity names are 4, 5 and 7 kW, each using a single-phase supply.
Outdoor and indoor equipment
The R290 refrigerant circuit stays in the outdoor unit. Indoor arrangements include wall-hung, pre-plumbed-cylinder and hybrid equipment. The indoor selection determines which pumps, buffer volume, backup heater, hot-water storage and boiler integration are present.
The outdoor unit measures 800 mm high, 1,100 mm wide and 540 mm deep and weighs 143 kg. The maximum heat-pump flow temperature is 75°C. That limit does not state the output or efficiency available at 75°C under every outdoor condition.
Sound power is 40 dB(A) for the 4 kW unit and 42 dB(A) for the 5 and 7 kW units. Lower sound-pressure figures apply at one metre; sound power and sound pressure are not interchangeable.
Exact certified combinations
The MCS directory held three outdoor-only ORE-S records and eight OR-S plus named cylinder combinations on 23 July 2026. All used certificate references MCS HP0329/05 to /15 and showed no end date. A matching capacity alone does not make every indoor unit an equivalent certified arrangement. The CS5800iAW codes page maps the exact outdoor and indoor combinations to their certificate references.
Worcester Bosch’s August 2025 supply notice said sales of its domestic cylinders, including named CS5800i pre-plumbed products, had ceased after the cylinder supplier entered liquidation. Existing installations remained supported. Current product pages still display cylinder packages, but do not confirm current supply of every cylinder and code.
Controls and guarantee
HomeCom Easy supports applicable remote monitoring. Worcester Bosch notes that monitoring may cease automatically after 12 months, so long-term connectivity should not be assumed without the current service terms.
Current guarantee terms provide a minimum two years. Manufacturer material describes up to seven years subject to training and other terms.
Related entries
Manufacturer and reference sources
Brand
Reference type
Heat-pump or fixed-AC model
Last reviewed
31 Jul 2026
Current status
Current in the manufacturer's UK range.