Worcester Bosch Greenstar 34CDi Classic

What is the Greenstar 34CDi Classic?

The Greenstar 34CDi Classic is a wall-mounted gas combi boiler, designed to provide heating and instant hot water without the need for a separate cylinder or tank. Sitting one step up from the 29CDi Classic in the CDi range, it offered a higher hot water flow rate, making it a better choice for homes with slightly greater hot water demand.

As a combi boiler, it heats water on demand directly from the mains. This makes it a practical and space-saving choice for homes without a hot water cylinder, and means there is no stored hot water to run out of.

The 34CDi Classic was part of the Greenstar CDi Classic range, which won the Which? Best Buy award multiple times and set the benchmark for combi boiler efficiency in the UK.

> Explore the full Worcester Bosch Greenstar range

Greenstar 34CDi Classic: Key Specifications

Boiler type: Combi boiler

Central heating output: 30kW

Hot water output: 34kW

Efficiency rating: A rated / 92%

Fuel type: Natural gas or LPG

Dimensions: 760mm x 440mm x 360mm

Flow rate: 14.3 litres per minute

Frost protection: Yes

Smart control compatible: Yes, including Bosch EasyControl

Suitable for: 2 to 4 bed homes, up to 12 radiators, 1 to 2 bathrooms

Who is this boiler suitable for?

The 34CDi Classic was designed for small to medium homes with a moderate to higher demand for hot water. It is best suited to properties with:

• 2 to 4 bedrooms
• 1 to 2 bathrooms
• Up to 12 radiators
• No existing hot water cylinder
• Standard mains water pressure

The higher flow rate of 14.3 litres per minute compared to the 29CDi Classic makes this model a stronger choice for homes that regularly run a bath and shower at the same time. If you already have a 34CDi Classic 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 34CDi Classic

Although the 34CDi Classic 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 and surrounding areas.

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 34CDi Classic 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 34CDi Classic

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 34CDi Classic has been replaced by the Worcester Bosch Greenstar 4000, which offers meaningful improvements across efficiency, warranty and controls.

The Greenstar 4000 30kW is the natural modern equivalent for homes currently running a 34CDi Classic. It delivers better efficiency, a longer warranty and full compatibility with the Bosch EasyControl smart thermostat.

Greenstar 34CDi Classic vs Greenstar 4000 30kW

Efficiency: 92% 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 CDi Classic models, across Buckinghamshire, Berkshire and surrounding areas.

• 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 34CDi Classic

Is the Worcester Bosch Greenstar 34CDi Classic still available to buy?

No. The 34CDi Classic is no longer manufactured. The modern equivalent is the Worcester Bosch Greenstar 4000 30kW combi boiler, which offers improved efficiency and a longer warranty.

Can the Greenstar 34CDi Classic still be serviced?

Yes. Parts remain widely available and our Gas Safe engineers service and repair all CDi Classic models across Buckinghamshire and Berkshire. Annual servicing is recommended to maintain efficiency and safety.

What replaced the Greenstar 34CDi Classic?

The Greenstar 34CDi Classic 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 34CDi Classic?

The 34CDi Classic achieves 92% seasonal efficiency with an ErP A rating. Modern replacements such as the Greenstar 4000 achieve up to 94%, which can make a noticeable difference to running costs over time.

What size home is the Greenstar 34CDi Classic suitable for?

The 34CDi Classic is suited to 2 to 4 bedroom homes with 1 to 2 bathrooms and up to 12 radiators. For larger properties with greater hot water demand, the 42CDi Classic was the more appropriate choice within the same range.

How long should a Greenstar 34CDi Classic last?

With regular annual servicing, a well-maintained 34CDi Classic 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.