System Boiler
iS Boiler System
i15S i18S i24S i32S i40SEvery ATAG boiler carries a 12-year warranty as standard with options up to 18 years and they’re professionally installed by our ATAG Selected Partners.
With an ATAG iS system boiler you’ll be choosing one of the most energy efficient boilers in Europe and you’ll love its easy to operate simplicity too.
What makes our system boilers different, though, is the in-built ErP pump. This controls the heat given out by the boiler, ensuring your boiler is as energy efficient as possible, saving you money year-on-year.
System boilers are traditionally fitted with an unvented hot cylinder which provides an increased capacity of hot water. The fact that the pump and controls are contained within the boiler casing counts towards a simple and space saving solution.
Key features and benefits
Compact dimensions
h700 x w440 x d366 (mm)
Five models available
15kW, 18kW, 24kW, 32kW, 40kW
Up to 18 years warranty
Including all parts and labour
Completely user friendly
with intuitive controls
Quiet in operation
Due to bottom-up modulation
Frost protection
With built-in frost protection
ErP "A" rated
Achieves ErP ‘A’ rating for heating and hot water
Loved by customers
ATAG is the UK’s highest rated boiler brand on Trustpilot
- A 275 mm (deep) model is available to fit inside kitchen cupboards
- 12 years warranty as standard with options up to 18 years
- Control the system via smartphone using the ATAG ONE Zone
- ATAG iCon stainless steel heat exchanger – with its unique lifetime replacement guarantee
- Detailed fault codes on LCD display for quicker, more accurate boiler diagnostics
- Fully compatible with ATAG iSteel cylinder range & the 3 port valve kit
- Built-in anti-cycling function for improved efficiency
- Combined condensate and pressure relief valve outlet pipe means less pipework
- Fully compatible with solar thermal hot water systems and ATAG iSteel twin coil cylinder range
- Supplied with fixing jig as standard, for rear piping up behind the boiler
- Factory fitted ErP-ready pump for low electrical consumption and improved efficiency
Specifications
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PART NUMBER
BS300158
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY CLASS
A
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY (%)
93
CH OUTPUT KW (50/30°C)
14.7
SEDBUK 2009 (%)
89.8
DIMENSIONS (H X W X D) MM
700X440X355
BOILER LIFT WEIGHT WITH JIG (KG)
39
STANDARD WARRANTY (YEARS)
12
LPG CONVERSION KIT AVAILABLE
YES
NOX CLASS
6
INGRESS PROTECTION (IP)
IPPX4D
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 60/100MM
18
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 60/100MM
18
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 80/125MM
50
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 80/125MM
50
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PART NUMBER
BS300118
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY CLASS
A
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY (%)
93
CH OUTPUT KW (50/30°C)
17.5
SEDBUK 2009 (%)
89.8
DIMENSIONS (H X W X D) MM
700X440X355
BOILER LIFT WEIGHT WITH JIG (KG)
39
STANDARD WARRANTY (YEARS)
12
LPG CONVERSION KIT AVAILABLE
YES
NOX CLASS
6
INGRESS PROTECTION (IP)
IPPX4D
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 60/100MM
18
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 60/100MM
18
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 80/125MM
50
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 80/125MM
50
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PART NUMBER
BS300124
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY CLASS
A
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY (%)
94
CH OUTPUT KW (50/30°C)
23.2
SEDBUK 2009 (%)
89.8
DIMENSIONS (H X W X D) MM
700X440X355
BOILER LIFT WEIGHT WITH JIG (KG)
39
STANDARD WARRANTY (YEARS)
12
LPG CONVERSION KIT AVAILABLE
YES
NOX CLASS
6
INGRESS PROTECTION (IP)
IPPX4D
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 60/100MM
18
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 60/100MM
18
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 80/125MM
50
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 80/125MM
50
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PART NUMBER
BS300132
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY CLASS
A
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY (%)
94
CH OUTPUT KW (50/30°C)
31.2
SEDBUK 2009 (%)
89.8
DIMENSIONS (H X W X D) MM
700X440X355
BOILER LIFT WEIGHT WITH JIG (KG)
42
STANDARD WARRANTY (YEARS)
12
LPG CONVERSION KIT AVAILABLE
YES
NOX CLASS
6
INGRESS PROTECTION (IP)
IPPX4D
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 60/100MM
6
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 60/100MM
6
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 80/125MM
45
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 80/125MM
45
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PART NUMBER
BS300140
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY CLASS
A
ERP SEASONAL SPACE HEATING ENERGY EFFICIENCY (%)
94
CH OUTPUT KW (50/30°C)
38.8
SEDBUK 2009 (%)
89.8
DIMENSIONS (H X W X D) MM
700X440X355
BOILER LIFT WEIGHT WITH JIG (KG)
42
STANDARD WARRANTY (YEARS)
12
LPG CONVERSION KIT AVAILABLE
YES
NOX CLASS
6
INGRESS PROTECTION (IP)
IPPX4D
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 60/100MM
6
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 60/100MM
6
MAXIMUM EQUIVALENT HORIZONTAL FLUE LENGTH (M) 80/125MM
45
MAXIMUM EQUIVALENT VERTICAL FLUE LENGTH (M) 80/125MM
45
OneZone
Control the temperature in your home remotely using the ATAG One Zone App, available for FREE on the App Store or Google Play
OneZone smart controllerCylinders
Need replacement cylinders? Check out our range to see which one your boiler requires.
View all cylindersComplete care
Ask your ATAG installer about the complete care pack, including the ONEZone smart controller, to increase your standard warranty from 12 to 18 years.
Find out moreInstallers that you can depend on
From design through to installation and after-care service, our ATAG selected gas-safe installers are on hand to offer you excellent advice and the best solution possible that suits your needs.
Find an installer