Worcester Bosch Greenstar 30Si Compact

What is the Greenstar 30Si Compact?

The Greenstar 30Si Compact is a wall-mounted gas combi boiler designed for smaller homes and apartments where space is at a premium. It was the successor to the original Greenstar Si range and was specifically engineered to fit inside a standard kitchen cupboard while still delivering reliable heating and hot water performance.

The 30Si Compact featured Worcester Bosch’s innovative WB7 heat exchanger, which allowed it to achieve a flow rate of 12.3 litres per minute despite its compact size. It provided instant hot water on demand from the mains without the need for a separate cylinder or storage tank.

The Si Compact range was a popular choice for landlords, flat owners and homeowners in smaller properties looking for a dependable, space-saving boiler from a trusted brand.

> Explore the full Worcester Bosch Greenstar range

Greenstar 30Si Compact: Key Specifications

✔ Boiler type: Combi boiler

✔ Central heating output: 24kW

✔ Hot water output: 30kW

✔ Efficiency rating: A rated / 94%

✔ Fuel type: Natural gas or LPG

✔ Dimensions: 690mm x 390mm x 280mm

✔ Flow rate: 12.3 litres per minute

✔ Frost protection: Yes

✔ Smart control compatible: Yes, including Bosch EasyControl

✔ Suitable for: 1 to 3 bed homes, up to 10 radiators, 1 bathroom

Who is this boiler suitable for?

The 30Si Compact was designed for smaller properties where space was limited and hot water demand was modest. It is best suited to properties with:

• 1 to 3 bedrooms
• 1 bathroom
• Up to 10 radiators
• No existing hot water cylinder
• Limited installation space, such as a kitchen cupboard

For homes needing slightly more hot water performance, the 25Si Compact offered a similar footprint with a comparable output. If you already have a 30Si Compact installed and are unsure whether to service, repair or replace it, our engineers can assess your system and give you honest advice.

Servicing and repairing your Greenstar 30Si Compact

Although the 30Si Compact is no longer manufactured, it can still be serviced and repaired. Parts remain widely available for this model and our Gas Safe engineers carry out full services and fault diagnosis across Buckinghamshire, Berkshire, West London and surrounding counties.

Regular servicing is important for any boiler, but particularly for older models. An annual service helps to:

• Maintain efficiency and keep running costs down
• Identify worn components before they cause a breakdown
• Keep your boiler operating safely
• Satisfy any remaining warranty or insurance requirements

> Book a boiler service

If your 30Si Compact has developed a fault, our engineers carry a wide range of Worcester Bosch parts and aim to resolve most repairs in a single visit.

> Book a boiler repair

When to consider replacing your 30Si Compact

If your boiler is over 12 to 15 years old or experiencing repeated breakdowns, replacement is often the more cost-effective long-term decision. The 30Si Compact has been replaced by the Worcester Bosch Greenstar 4000, which offers meaningful improvements across efficiency, warranty and controls while maintaining a compact footprint.

The Greenstar 4000 25kW is the natural modern equivalent for homes currently running a 30Si Compact. It delivers better efficiency, a longer warranty and full compatibility with the Bosch EasyControl smart thermostat.

Greenstar 30Si Compact vs Greenstar 4000 25kW

Efficiency: 94% vs up to 94%

Warranty: 2 to 5 years vs up to 10 years

Controls: Basic display vs smart control ready

ErP rating: A rated vs A rated

Status: Discontinued vs current model

> Learn more about the Greenstar 4000

> View boiler costs

> Explore finance options

Why choose Heppelthwaite – Red Van Plumbers?

Fewer than 5% of UK installers achieve Worcester Bosch Platinum Accredited status. As Platinum Accredited Installers, we install, service and repair the full Greenstar range, including legacy Si Compact models, across Buckinghamshire, Berkshire, West London and surrounding counties.

• Platinum Accredited Worcester Bosch Installers
• Family-run business established 1948
• Gas Safe registered engineers
• Free fixed quotations with no hidden costs
• Up to 10-year warranty available on new Greenstar 4000 installations

> Request a free quote or call 01628 533 550

FAQs – Worcester Bosch Greenstar 30Si Compact

Is the Worcester Bosch Greenstar 30Si Compact still available to buy?

No. The 30Si Compact is no longer manufactured. The modern equivalent is the Worcester Bosch Greenstar 4000 25kW combi boiler, which offers an improved warranty and smart control compatibility while maintaining a compact design.

Can the Greenstar 30Si Compact still be serviced?

Yes. Parts remain widely available and our Gas Safe engineers service and repair all Si Compact models across Buckinghamshire, Berkshire and West London. Annual servicing is recommended to maintain efficiency and safety.

What replaced the Greenstar 30Si Compact?

The Greenstar 30Si Compact was replaced by the Worcester Bosch Greenstar 4000. The 4000 offers up to 94% efficiency, smart control compatibility and up to a 10-year warranty when installed by a Platinum Accredited Installer.

How efficient is the Greenstar 30Si Compact?

The 30Si Compact achieves 94% seasonal efficiency with an ErP A rating, which was considered excellent performance for a compact boiler. The Greenstar 4000 matches this efficiency while offering a significantly longer warranty.

Will the Greenstar 30Si Compact fit in a kitchen cupboard?

Yes. The 30Si Compact was specifically designed to fit inside a standard kitchen cupboard at 690mm x 390mm x 280mm. This compact footprint made it one of the most popular choices for smaller homes and apartments where wall space was limited.

How long should a Greenstar 30Si Compact last?

With regular annual servicing, a well-maintained 30Si Compact can last between 12 and 15 years. If your boiler is approaching or has exceeded this age, it may be worth considering a boiler replacement to avoid repeated repair costs.