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Worcester Bosch Greenstar Heatslave II Oil Combi Boiler 12/18–25/32kW
£3,519.99
Taxes included.
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30-day return policy
Pickup available at F3 Castings Way, Leafbridge, Castings Way, Lincoln
Usually ready in 24 hours
Supplied to order. Order-in boilers are usually with us in 2-4 working days. We confirm availability and the delivery or collection date when you order.
Worcester Bosch Greenstar Heatslave II Oil Combi Boiler 12/18–25/32kW
The Greenstar Heatslave II is Worcester Bosch's internal floor-standing oil condensing combi, with a built-in stainless steel hot water store for fast mains-pressure hot water. It suits off-gas homes and fits under a kitchen worktop (the worktop must be removable).
Key points
- Outputs 12/18, 18/25 and 25/32kW (2022+ models)
- 855 x 520 x 600mm (H x W x D), IP20, ErP A for heating
- Hot water flow rates of 15, 18 and 22 (Worcester's figures by model)
- EasyControl and solar compatible; HVO conversion kits available from Worcester
- Room-sealed Oilfit 80/125 flue (up to 6m horizontal, 8m vertical) or conventional flue
Required with this boiler: a flue kit
Worcester Bosch supplies this boiler without a flue. The Flue kit selector above Add to cart adds the Greenstar Oilfit 80/125 standard telescopic flue kit (460-670mm, 7716190064) by default, as a separate line in your basket. Pick the short telescopic kit (360-460mm) for thinner walls, or the Oilfit 80/125 vertical flue kit for a roof exit.
Only choose "I already have this" if you already have a compatible Oilfit flue, or the boiler is going onto a conventional (open) flue. Check maximum flue lengths and terminal positions in the installation manual.
What's included
- 1 x Worcester Bosch Greenstar Heatslave II oil combi boiler in the output you select
- Flue damper, hardware pack, ErP label and literature, as supplied by Worcester Bosch
- No flue included: choose your flue kit with the selector above Add to cart
Specification and price
Dimensions (H x W x D): 855 x 520 x 600mm. Fuel: kerosene (class C2). Minimum mains inlet pressure 1.2-1.6 bar depending on model.
| Model | Output (CH / DHW) | Part number | Our code | Price (inc VAT) |
|---|---|---|---|---|
| 12/18 | 18kW / 18kW | 7731600260 | PLUMHEAT0424 | £3,519.99 |
| 18/25 | 25kW / 25kW | 7731600261 | PLUMHEAT0425 | £3,811.99 |
| 25/32 | 32kW / 32kW | 7731600262 | PLUMHEAT0426 | £4,129.99 |
Recommended add-ons
Tick these in the add-on list above Add to cart, or follow the links:
- Worcester Bosch EasyControl CT200 smart thermostat: app and smart control; in stock in Lincoln.
- Worcester Bosch Greenstar magnetic system filter: protects the system and is required for Worcester's extended guarantee.
- Worcester Bosch Comfort+ II RF programmable thermostat: wireless programmable room control.
- Oilfit plume management kit: moves the plume away from windows and boundaries.
- Oilfit 80/125 1m extension and 90° bend: for longer or offset flue runs.
Installation and guarantee
Installation must be by a Gas Safe registered engineer (oil: OFTEC registered) and commissioned with the Benchmark checklist. Manufacturer guarantees require registration after installation and annual servicing; extended guarantee terms are the manufacturer's and may require their approved filter/installer.
Oil installations also need a correctly sited tank and oil supply line with filter, isolation and a remote-sensing fire valve, to BS 5410 and Building Regulations. Worcester Bosch's current UK product page quotes up to a 7 year guarantee (2 years standard; longer terms need a Greenstar System Filter and Worcester's registration terms).
Delivery and collection
Delivered by pallet/courier (£29.99 per order) or collect free from Leafbridge, Lincoln. Order-in boilers usually 2-4 working days.
Worcester Bosch's Heatslave II internal operating instructions and the 12/18 ErP data sheet are in the PDF downloads at the bottom of this page.
Shop the Worcester Bosch Greenstar oil range
- Greenstar Heatslave II External oil combi
- Greenstar Danesmoor Utility regular
- Greenstar Danesmoor Utility System
- Greenstar Danesmoor External regular
- Greenstar Danesmoor External System
- Greenstar Utility 32/50 and 50/70 regular
Flues and accessories: Oilfit telescopic flue kit · vertical flue kit · plume kit · terminal guard · support bracket. Browse all boilers and central heating controls.
PDF Downloads
Manufacturer documents for this product.
