Worcester Bosch Greenstar 8000+ System Boiler Cost with Installation

The Greenstar 8000+ is Worcester Bosch’s top-of-range system boiler – the step up from the 4000 for larger homes, higher demand, and homeowners who want the longest warranty Worcester Bosch offers: 12 years with an Accredited Installer, two more than the 4000 achieves.

Available in 30kW and 35kW, it comes with a full-colour touchscreen display as standard, an Intelligent Filling System that automatically maintains system pressure, and built-in WiFi. The cylinder, filter, and flue are separate purchases.

See more of the Worcester Bosch Greenstar 8000 system boiler specifications below:

Worcester Bosch Greenstar 8000+ System Boiler Product Table
	Output	30kW	35kW
	Type	System	System
	Fuel	Gas / LPG	Gas / LPG
	Condensing	Yes	Yes
	Efficiency rating (%)	94	94
	ErP	A	A
	Standard guarantee	5 years	5 years
	Max guarantee	12 years*	12 years*
	Max output (kW)	30	35
	DHW flow rate	Determined by cylinder
	Mounting	Wall-mounted
	Dimensions (mm)	780 x 440 x 365
	Display	Full-colour touchscreen	Full-colour touchscreen
	Intelligent Filling System	Yes
	Typical price (incl. flue)	£1,400	£1,550
	Typical installation cost (incl. VAT)	£1,500
	Total cost	£2,900	£3,050

*12-year guarantee when installed by a Worcester Bosch Accredited Installer with a Greenstar System Filter fitted. Terms and conditions apply.

Worcester Bosch Greenstar 8000+ System Boiler overview

The 8000+ occupies a specific position in the Worcester Bosch range: it’s the right boiler for homes that need more than the 4000 System’s 24kW ceiling and for homeowners who want the 12-year maximum warranty. The touchscreen display, Intelligent Filling System, and built-in WiFi all come as standard – this isn’t a stripped-back entry model with an 8000 badge on it.

If you’re replacing a Greenstar i System 30 or 35, the 8000+ drops onto existing pipework with Simple Switch compatibility. If you’re choosing between the 4000 System and the 8000+, the question is straightforward: need more than 24kW or want 12 years of warranty cover rather than 10? The 8000+. Happy with the 4000’s output ceiling and 10-year tier? Save £300 and stay with the 4000.

Worcester Bosch Greenstar 8000+ System Boiler Range
Model	Suitable for	Radiators	Notes
30kW	Medium-large homes, 3-4 bedrooms	Up to 20	Suits homes with 2+ bathrooms using stored cylinder hot water
35kW	Large homes, 4+ bedrooms	Up to 20+	Higher heat demand properties with higher heat loss

Output selection for a system boiler is based on your property’s heat loss, not the number of bathrooms – the cylinder handles that separately. A Gas Safe engineer calculates the correct output at survey stage. The 30kW is the starting point for most large family homes; the 35kW suits properties with higher heat demand or older, less well-insulated stock.

Key benefits at a glance

• ErP A-rated efficiency (94% efficient)
• 12-year maximum warranty with Accredited Installer – the longest Worcester Bosch offers
• Available in 30kW and 35kW – higher output ceiling than the Greenstar 4000 System
• Full-colour touchscreen display as standard
• Intelligent Filling System – automatically maintains system pressure
• LPG compatible across all variants
• Internal pump and expansion vessel
• Simple Switch compatible with Greenstar i System 30 and 35
• Quiet Mark certified
• EasyControl app compatible
• Compatible with Nest, tado, Hive, Amazon Alexa, and Google Home Assistant
• 5-year standard warranty, up to 12 years with Accredited Installer and Greenstar System Filter
• Hydrogen blend ready (up to 20%)

Worcester Bosch Greenstar 8000+ Boiler technical specifications

The 8000+ builds on the established 8000 platform with a full-colour touchscreen as standard across the range, the Intelligent Filling System, and enhanced connectivity. The key differences from the 4000 System are the output ceiling (30-35kW vs 12-24kW) and the maximum warranty length (12 years vs 10). Everything else – 94% efficiency, internal pump and expansion vessel, Quiet Mark certification – is consistent with the wider Worcester Bosch premium range.

Output and efficiency ratings

Both outputs run at 94% ErP A-rated efficiency. As condensing boilers, they recover heat from exhaust gases that older non-condensing boilers vented outside – the source of meaningful bill reductions for homeowners replacing pre-2005 installations.

The 30kW suits most large family homes with a cylinder already in place. The 35kW is appropriate for larger properties with higher heat loss or older, less well-insulated stock where a 30kW would struggle to maintain temperature in severe cold. Your Gas Safe engineer will calculate the correct output from a heat loss assessment – over-specifying wastes energy; under-specifying means the boiler runs flat-out and still falls short.

Dimensions and installation

At 780mm tall, 440mm wide, and 365mm deep, the 8000+ is larger than the 4000 System (724 x 400 x 310mm) across every dimension. It’s still wall-mounted and still fits a standard boiler position, but confirm cupboard dimensions at survey stage – particularly depth and height clearances. Simple Switch compatibility with the Greenstar i System 30 and 35 makes like-for-like replacements on those specific models straightforward, reusing existing pipework connections.

Components and controls

The internal pump and expansion vessel are housed within the boiler casing – the same self-contained configuration as the 4000 System, keeping the wall-mounted installation clean without separate external components. Quiet Mark certification means the 8000+ operates at low noise levels suitable for kitchen and utility space installations.

The EasyControl app provides remote temperature adjustment, scheduled programming, and energy usage tracking. Voice control via Amazon Alexa and Google Home Assistant is supported. Nest, tado, and Hive integrate via the standard thermostat interface.

The Intelligent Filling System automatically monitors and maintains system pressure without the homeowner needing to top up via a filling link. On the 4000 System this is manual; on the 8000+ it’s handled automatically – one less thing to think about.

The 12-year maximum warranty is activated by an Accredited Installer registering the boiler alongside a Greenstar System Filter within 30 days of installation. Annual servicing by a Gas Safe registered engineer is required to maintain the extended cover. The filter is not included in the box – budget £100-£120 and confirm it’s in the installation quote.

Prices and installation costs

The Greenstar 8000+ System costs approximately £1,400 for the 30kW and £1,550 for the 35kW, including a standard horizontal side-wall flue. These are boiler-only prices – the Greenstar System Filter and hot water cylinder are separate purchases. A vertical roof flue adds £300-£500 where a side-wall exit isn’t available.

Using a mid-range installation figure of £1,500:

Worcester Bosch Greenstar 8000+ System Boiler Costs
Output size	Unit cost (incl. flue)	Total (incl. installation)
30kW	£1,400	£2,900
35kW	£1,550	£3,050

These prices assume a like-for-like system boiler replacement with an existing cylinder in place. A new unvented cylinder adds £500-£1,000 plus fitting. Converting from a combi with no existing cylinder can add up to £2,000 to the project cost.

These prices are indicative, based on our research and actual boiler prices submitted to WhatPrice by homeowners. For a broader overview of Worcester Bosch pricing across the full range, see our Worcester Bosch boiler prices guide. Get quotes from at least three Gas Safe registered installers, or use the WhatPrice Boiler Cost Calculator for a guide price.

Warranty and support

Five years standard. Twelve years with a Worcester Bosch Accredited Installer, a registered Greenstar System Filter, and annual servicing by a Gas Safe engineer. That 12-year maximum is the longest Worcester Bosch offers on any boiler and two years more than the 4000 System’s top tier. For a boiler at this price, that extended cover is a meaningful part of the value proposition.

The filter must be fitted and registered at installation – not added later. Confirm Accredited installer status before booking, and ensure the filter is itemised in the quote. Registration must be completed within 30 days of installation.

Installation information

A like-for-like system boiler replacement on existing pipework is a one-day job. For Greenstar i System 30 and 35 replacements, Simple Switch compatibility means the 8000 drops onto existing connections. The 8000+’s larger dimensions (780mm vs 724mm tall, 365mm vs 310mm deep) are worth checking against the available space if the existing boiler is a 4000 or earlier model.

What to expect on installation day

Do you need a system flush or filter?

A magnetic filter is mandatory under UK Building Regulations on any new boiler installation – and for the Greenstar 8000+, fitting the Greenstar System Filter is the condition that unlocks the 12-year warranty. It doesn’t come in the box. Make sure it’s in the installation quote from day one.

A powerflush isn’t legally required but we’d recommend it on systems over ten years old. Budget £350-£800 depending on the number of radiators.

Finding a Gas Safe registered engineer

All gas boiler installations must be carried out by a Gas Safe registered engineer. For the 12-year warranty, the installer must hold Worcester Bosch Accredited status or the £40 non-WAI route must be taken through Worcester directly. For a new unvented cylinder, a G3 qualification is additionally required. Use the WhatPrice quote service to be matched with vetted, Gas Safe registered installers in your area.

Reviews and ratings

Worcester Bosch holds a 4.6 out of 5 rating on Trustpilot UK, based on over 50,000 reviews. The 8000+ is a premium product and generates less volume of model-specific feedback than the 4000 range – the broader Worcester Bosch system boiler feedback applies, with the same themes that run across the range.

Positive reviews

Worcester Bosch’s engineer quality and response times are the consistent positive across the system boiler pool. Faults diagnosed quickly, parts carried in the van, first-visit resolution under warranty. Which? has named Worcester Bosch a Best Buy for over a decade – a recognition that reflects sustained performance in reliability and customer satisfaction data rather than any single model.

Homeowners who opt for the 8000 over the 4000 specifically cite the 12-year warranty as the deciding factor. On a boiler at this price point, having manufacturer cover for over a decade without revisiting the market for an extended plan has genuine value – and several reviewers note this as the point that justified the step up from the 4000.

Negative reviews

The same warranty condition frustration that affects the 4000 range applies here. The 12-year figure is prominently marketed, but it requires both Accredited installer status and a registered filter. Homeowners who discover the 5-year standard applies after a fault – because one condition wasn’t met at installation – are understandably frustrated. Confirm both in writing before the job starts.

Setup complexity is a known friction point across the Greenstar 8000 range, as it is on the 4000. Ask your engineer to complete the setup before leaving.

How the Worcester Bosch Greenstar 8000+ Boiler compares

Worcester Bosch Greenstar 8000+ System Boiler Comparison Table
Model	Worcester Bosch Greenstar 8000+ System	Worcester Bosch Greenstar 4000 System	Vaillant ecoTEC plus System
Typical unit price (30kW)	£1,400	£1,100	£1,150
Heat exchanger	Aluminium	Aluminium	Stainless steel
Standard warranty	5 years	5 years	5 years
Max warranty	12 years	10 years	10 years
Built-in WiFi	Yes	Yes	No
App control	EasyControl (built-in)	EasyControl (built-in)	vSMART (optional)
Display	Full-colour touchscreen	LCD colour	LCD
Max system output	35kW	24kW	35kW
LPG compatible	Yes	Yes	Yes

For personalised guidance on choosing the right boiler, we recommend speaking with a Gas Safe registered engineer.

Final thoughts – is the Worcester Bosch Greenstar 8000+ right for you?

The 8000+ earns its premium over the 4000 System in two specific ways: the higher output ceiling (up to 35kW vs 24kW) and the 12-year maximum warranty. If your home needs more than 24kW, the 4000 simply isn’t an option. If you’re weighing the 4000 against the 8000+ on warranty alone, the question is whether two extra years of top-tier cover is worth £300 more upfront – for a boiler expected to run for 12-15 years, most homeowners would say yes.

Against the Vaillant ecoTEC plus System, the 8000+ is more expensive but adds two more years at the maximum warranty tier and includes built-in WiFi as standard – the ecoTEC plus requires a separate vSMART purchase for app control. The ecoTEC plus uses a stainless steel heat exchanger where the 8000+ uses aluminium, which is a specification point in Vaillant’s favour in hard water areas. For most homeowners choosing on warranty length and connectivity, the 8000+ is the stronger package. For those in hard water areas where the heat exchanger material matters long-term, the ecoTEC plus is worth serious consideration alongside it.

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