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 4.7 stars

1,247 reviews

 4.7 stars

1,247 reviews

Worcester Bosch Greenstar Heatslave II External 12/18 Combi Oil Boiler

Worcester Bosch Greenstar Heatslave II External 12/18 Combi Oil Boiler Boiler
Typical Price (inc VAT)
£2,458
Typical installation Cost (inc VAT)*
£1000 - £1500
Sundries (Filter, Flue, etc)
£300
Total Cost
£3,758 - £4,258

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Make Worcester Bosch
Model Greenstar Heatslave II External 12/18 Combi Oil Boiler
Is Condensing Condensing
Efficiency Rating 90%
Band Rating A Rating
LPG Compatible No
Standard Warranty Up to 5 Years
Central Heating Max. Output 18 kW
Mounting Floor Standing
Flow Rate 15 l/min
Typical Price (inc VAT) £2,458
Typical installation Cost (inc VAT)* £1000 - £1500
Sundries (Filter, Flue, etc) £300
Total Cost £3,758 - £4,258
ERP Rating A Heat B Water
Hot Water Max. Output 18 kW

* This is a guide price for a straightforward, like-for-like boiler replacement. Installation costs will vary dependent on work required.

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Worcester Bosch Greenstar Heatslave II External 12/18

The Greenstar Heatslave II External 12/18, manufactured by Worcester Bosch, is an oil-fired boiler designed for outdoor installation.

How efficient is the Heatslave II External 12/18?

The Worcester Bosch range of Heatslave II External boilers are highly efficient, as shown by the 90% efficiency. To put this into context, for every £1 spent on heating your home, only 10p is lost to waste gases produced during operation (this is something that happens with all oil and gas boilers). In addition to the high efficiency, Heatslave II External boilers have been handed an ErP A-rating for heat and B for hot water.

Is the output rating suitable for my home?

An 18 kW central heating output rating makes this model suitable for properties with a single bathroom and, as a combi, will deliver instant hot water as and when needed.

What options are available in the Greenstar Heatslave II External range?

Should you live in a larger property with a higher demand for heating and hot water then the Heatslave II External range also includes outputs of 25 kW and 32 kW. Indoor models are also available which have the same output ratings as the external units.

Is a combi boiler suitable for my home?

Combi boilers provide heating and hot water on demand using the mains water supply. As they don't store water in a cylinder, they can't meet higher demands for hot water which is why they're best suited to smaller properties. And, in the case of this 18 kW model, it's best suited to properties with 1 bathroom.

How long is the warranty?

Greenstar Heatslave II oil boilers come with a 2 year warranty as standard, which will see that you're covered after the installation. And in addition to that, the primary heat exchanger comes with a 5 year warranty.

What are the key features of the Heatslave II External 12/18?

As an external boiler the Heatslave II is housed in a green casing with IP45 protection to see that the unit is protected against the elements.

This boiler is well worth protecting as it has a number of great features, including an eco hot water mode to lower energy usage and keep your energy bills to a minimum, frost protection to keep it running through the cold winter months and it can fill a kitchen sink with hot water in only 22 seconds.

How big is the Heatslave II External?

The Heatslave II External has dimensions of 950 x 640 x 770mm (HxWxD)and as an outdoor combi boiler you'll be saving plenty of room in your property.

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Excellent 4.7 out of 5

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