Spring is finally here — and if last summer is anything to go by, it won't stay mild for long. The question is: do you spend another sweltering August regretting the fact you never sorted air conditioning, or do you actually do something about it this year? The good news is that a proper, wall-mounted split air conditioner doesn't have to cost a fortune — and the Worcester Bosch Climate 3000i is one of the clearest proofs of that.
This is a full reversible single-split unit: it cools in summer and heats in winter, making it a year-round climate solution rather than just a seasonal luxury. Four capacities cover everything from a compact home office to a large open-plan living room. Below, we'll walk through everything you need to know to pick the right size for your space.
What Is a Split Air Conditioner — and Why Should You Care?
Two units, one system
A split system has a slim wall-mounted indoor unit (the part you see in your room) connected by refrigerant pipes to a compact outdoor unit. No ducting, no ugly window unit blocking your view.
Inverter technology means lower bills
Rather than switching on and off at full power, an inverter compressor modulates continuously — hitting your target temperature and then coasting to maintain it. The Climate 3000i's A++ SEER rating of 7.4 means it's genuinely frugal with electricity.
Cooling AND heating from one unit
The 3000i is fully reversible. In heating mode it achieves a SCOP of 4.0–4.2, meaning it produces around four kilowatts of heat for every one kilowatt it draws from the wall. That's far more efficient than any electric panel heater.
Professional installation once, silent comfort forever
Installation requires an F-Gas certified engineer. Once fitted, you're left with a neat, silent system that requires very little ongoing maintenance beyond an annual filter clean.
What the Worcester Bosch Climate 3000i Actually Does
Worcester Bosch have packed a surprisingly long feature list into what is positioned as their entry-level split unit. Here's what you get as standard:
- i-clean mode — heats the evaporator to 56°C to eliminate up to 99% of bacteria, keeping internal components fresh without chemicals
- Double filtration — removes odours, volatile organic compounds, and harmful gases from circulated air
- Silent mode — reduces outdoor unit noise to just 20 dB(A) on the smaller models; ideal for night-time use and terraced houses with close neighbours
- Follow Me mode — a temperature sensor in the infrared remote reads the temperature at your exact location, so the unit adjusts to where you actually are rather than a fixed wall position
- Wind Avoid Me — redirects airflow towards the ceiling so you're never hit by a cold blast while relaxing on the sofa
- ECO & Gear modes — throttle back energy consumption when full power isn't needed; particularly useful for overnight use
- 8°C Heating mode — frost protection for conservatories, garages, or holiday cottages through the winter
- Auto restart — remembers your last settings after a power cut
- Anti-corrosion gold fin coating — protects the outdoor unit's heat exchanger fins, important near the coast or in urban environments with higher air pollution
- Wi-Fi ready — add the optional Connect Key G10 CL-1 accessory to control everything via the Bosch HomeCom Easy app
Which Size Do You Need?
The Climate 3000i comes in four output capacities. As a general rule, you need roughly 100–120W of cooling per square metre in a well-insulated UK home — though rooms with large south-facing windows, poor insulation, or multiple occupants may benefit from stepping up a size. Use our BTU calculator if you want a more precise figure.
The Worcester Bosch Climate 3000i Range
Each kit includes the indoor wall unit, outdoor condensing unit, and remote controller — everything you need for your F-Gas engineer to complete the installation. All models use R32 refrigerant (GWP 675), are EUROVENT certified, and carry Worcester Bosch's 5-year guarantee.*
Worcester Bosch
Climate CL3000i – 2.6 kW Single Split Kit
The perfect entry point for bedrooms, home offices, and compact living rooms up to 20 m². Whisper-quiet at 22 dB(A) on low speed — you'll barely notice it's running.
Worcester Bosch
Climate CL3000i – 3.5 kW Single Split Kit
The most popular size in the range. Ideal for master bedrooms, kitchens, and living rooms up to 30 m². SCOP of 4.2 makes it a cost-effective supplementary heat source too.
Worcester Bosch
Climate CL3000i – 5.3 kW Single Split Kit
Designed for larger living spaces, extensions, and open-plan kitchens up to 45 m². Handles ambient temperatures down to −15°C in heating mode with ease.
Worcester Bosch
Climate CL3000i – 7.0 kW Single Split Kit
Maximum power for large open-plan spaces, conservatories, and rooms up to 60 m². 7.3 kW heating output and SCOP 4.0 make this a serious all-season performer.
Full Technical Comparison
| Specification | 2.6 kW | 3.5 kW | 5.3 kW | 7.0 kW |
|---|---|---|---|---|
| Cooling capacity | 2.6 kW | 3.5 kW | 5.3 kW | 7.0 kW |
| Heating capacity | 2.9 kW | 3.8 kW | 5.6 kW | 7.3 kW |
| SEER (cooling efficiency) | 7.4 | 7.0 | 7.0 | 6.4 |
| SCOP (heating efficiency) | 4.1 | 4.2 | 4.0 | 4.0 |
| Cooling ErP class | A++ | A++ | A++ | A++ |
| Heating ErP class | A+ | A+ | A+ | A+ |
| Indoor sound (H/M/L/Silent) dB(A) | 37/32/22/20 | 37/32/22/21 | 41/37/31/20 | 46/37/34.5/21 |
| Outdoor sound level dB(A) | 55.5 | 55 | 57 | 60 |
| Cooling operating range | −15°C to +50°C | |||
| Heating operating range | −15°C to +24°C | |||
| Refrigerant | R32 (GWP 675) | |||
| Max. pipe run | 25 m | 25 m | 30 m | 50 m |
| Indoor unit dimensions (W×D×H) | 729×200×292 mm | 802×200×295 mm | 971×228×321 mm | 1082×234×337 mm |
| Power supply | 220–240V, 1-phase, 50Hz | |||
Nominal values measured to EN14511 and EUROVENT registered. SEER/SCOP per EN14825.
What Does It Cost to Run?
With a SEER of 7.4 and the UK electricity unit rate sitting at around 27p/kWh (Ofgem price cap, mid-2025), the 3.5 kW model's annual cooling cost works out to roughly £51 — based on 400 hours of cooling use per year. Add winter heating at around £142 for 600 hours of use (SCOP 4.2), and you're looking at a combined annual running cost of approximately £193. For context, running a 2 kW electric panel heater for the same 600 hours would cost around £324 in electricity alone.
Engaging ECO mode or the programmable timer to avoid heating or cooling an empty room can trim that figure significantly further.
A Note on Installation
By law, installation must be carried out by an F-Gas certified engineer who is qualified to handle the R32 refrigerant. The indoor unit mounts high on a wall for even air distribution; the outdoor unit is placed on the ground, a wall bracket, or a flat roof. Pipe runs of up to 25–50 metres (depending on the model) give installers real flexibility on where the outdoor unit goes. A typical single-room installation takes between four and eight hours.
If you'd like us to help coordinate installation, request a quote and we'll put you in touch with a local specialist.
Explore More from AIZO Quality Heating
Ready to stay cool this summer — and warm this winter?
Browse the full Worcester Bosch Climate 3000i range and find the right size for your space. Express UK delivery available.
Shop the Climate 3000i Range*5-year guarantee subject to Worcester Bosch terms and conditions. Nominal performance data measured per EN14511; SEER/SCOP per EN14825. R32 GWP 675. Installation by F-Gas certified engineer required.