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 4.8 stars

1,269 reviews

 4.8 stars

1,269 reviews

Mistral Sealed System Non-Condensing S3 35kW Oil Boiler

Mistral Sealed System Non-Condensing S3 35kW Oil Boiler Boiler
Typical Price (inc VAT)
£1,500
Typical installation Cost (inc VAT)*
£1000 - £1500
Sundries (Filter, Flue, etc)
£300
Total Cost
£2,800 - £3,300

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Make Mistral
Model Sealed System Non-Condensing S3 35kW Oil Boiler
Is Condensing Non-Condensing
Efficiency Rating 87%
Band Rating B Rated
LPG Compatible No
Standard Warranty 2 yr. parts - 5 yr. heat exch
Central Heating Max. Output 35kW
Mounting Floor Standing
Flow Rate N/A
Typical Price (inc VAT) £1,500
Typical installation Cost (inc VAT)* £1000 - £1500
Sundries (Filter, Flue, etc) £300
Total Cost £2,800 - £3,300
ERP Rating B Heat

* 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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Product Description

The Sealed System S3 is a non-condensing, floor-standing oil boiler that’s been designed and manufactured by Mistral. This is a compact unit, measuring just 410mm wide and is housed within a white high-quality casing.

With an efficiency rating of 93% which makes this an A rated unit, you’ll be getting a highly efficient boiler. An output rating of 35kW makes the S3 perfectly suited to larger homes with a higher demand for heating and hot water, as well as properties with multiple bathrooms. When choosing a boiler in this range, you have a lot of choice, from condensing or non-condensing units, indoor or outdoor installation and a range of outputs ranging from 15kW up to 41kW.

This unit comes with a variety of features to give it its high efficiency rating, some of these include a pre-installed heating sealed system, a circulating pump, 12 litre expansion vessel, safety valve, pressure gauge, an automatic air vent, 2 or 4 port option front servicing, multi-directional flue outlets, conventional or balanced flue options, pre-punched pipe access points, and can also be used in tandem operations.

As a System boiler, the S3 sends hot water to the radiators and a sealed hot water storage cylinder. The important parts of the system are built into the boiler which makes it more compact and easier to service.

Featuring a 5 year warranty, you can be

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Excellent 4.8 out of 5

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