BoschCS3800iAW 13 OE-T
The Bosch CS3800iAW 13 OE-T is an air-to-water heat pump with a SCOP of 5.04 (35 °C) and a sound power level of 51 dB(A). Under permitted development the limit is 37 dB(A) measured 1 m in front of the centre of a neighbour’s habitable-room door or window. Free-standing, the indicative minimum distance is 2.0 m; against a wall 2.8 m.1
Key figures
Rules in the UK
Minimum distance to your neighbour
MCS 020(a) (England, permitted development since 29 May 2025)2 · 1 m in front of the centre of a neighbour’s habitable-room door or window
Indicative calculation (hemispherical, no barriers). Not a substitute for an MCS 020 assessment.
Boiler Upgrade Scheme
Check conditions£7,500 – £9,0003Fixed grant (England & Wales)
Fixed grant in England and Wales, deducted from your installer’s quote. £9,000 when replacing oil or LPG off the gas grid (until March 2027). Scotland: Home Energy Scotland grant instead.4,5
- Must be MCS-certified (product and installer). Check the Ofgem product eligibility list.
- Rated output 12.5 kW; the scheme covers systems up to 45 kW.
- SCOP at 55 °C: 3.88. The installed system needs a SCOP of at least 2.8 (MCS calculation).
Technical specifications
| General | |
|---|---|
| Type (source) | Air-to-water1 |
| Performance | |
| Heating capacity (A7/W35) | 11.05 kW1 |
| Rated output 35 °C | 12.5 kW1 |
| Rated output 55 °C | 12.5 kW1 |
| Min. outdoor temperature | -22 °C1 |
| Efficiency | |
| SCOP (35 °C) | 5.041 |
| SCOP (55 °C) | 3.881 |
| Seasonal efficiency ηs 35 °C | 199 %1 |
| Seasonal efficiency ηs 55 °C | 152 %1 |
| Energy label 35 °C | A, , , 1 |
| Energy label 55 °C | A, , , 1 |
| COP A7/W35 | 4.461 |
| Noise | |
| Outdoor unit sound power | 51 dB(A)1 |
| Indoor unit sound power | 34 dB(A)1 |
| Refrigerant | |
| Refrigerant | R2901 |
| Refrigerant GWP | 31 |
| Refrigerant charge | 1.37 kg1 |
Variants
This model is registered in 4 combinations (for example with a different indoor unit or cylinder) with exactly the same performance. All figures on this page apply to each of these types. The part of the type number that differs is in bold; small differences (e.g. cylinder volume or anode) are listed after it:
- CS3800iAW 13 OE-T
- CS3800iAW 13 OM-T — Indoor unit sound power: 40 dB(A)
- CS3800iAW 13 OMH-T — Indoor unit sound power: 40 dB(A)
- CS3800iAWF 13 O-T HPC800i S
Manufacturer documentation
- Brochure / leaflet — Luft-Wasser-Wärmepumpe Compress 3800i AW – Broschüre
External links to Bosch's official website. The manufacturer may change or move documents; where they differ, the manufacturer's latest version applies.
Frequently asked questions
Can I install the Bosch CS3800iAW 13 OE-T without planning permission?
Under MCS 020(a) (England, permitted development since 29 May 2025) the unit must not exceed 37 dB(A) 1 m in front of the centre of a neighbour’s habitable-room door or window. With a sound power of 51 dB(A) that indicatively means 2.0 m free-standing, 2.8 m against a wall or 4.0 m in a corner. Your MCS installer must confirm this.1
How much Boiler Upgrade Scheme grant can you get for the Bosch CS3800iAW 13 OE-T?
£7,500 in England and Wales, provided the product and installer are MCS-certified (£9,000 when replacing oil or LPG off the gas grid, until March 2027). The installer applies and deducts the grant from your quote.1
Which refrigerant does the Bosch CS3800iAW 13 OE-T use?
The Bosch CS3800iAW 13 OE-T uses R290.1
Sources
- Heat Pump Keymark certificates — EHPA / DIN CERTCO (Heat Pump KEYMARK) · accessed 29 Sept 2026
- MCS 020(a) (England, permitted development since 29 May 2025)
- Boiler Upgrade Scheme: what you can get — GOV.UK · accessed 27 Sept 2026
- Boiler Upgrade Scheme: guidance for installers (V5) — Ofgem · accessed 27 Sept 2026
- Boiler Upgrade Scheme product eligibility — Ofgem · accessed 27 Sept 2026