ATAG iS system boilers are available in various outputs from 15 kW to 40 kW and are suitable for most property sizes regardless of the hot water demand.

With an ATAG iS, not only are you selecting one of the most energy efficient boilers in Europe, but you’ll love its easy to operate simplicity too.

System boilers work by heating your home’s hot water and central heating system. The addition of the cylinder means you have access to hot water as and when you need, in the volume required to cope with multiple bathrooms.

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. Customers seeking even more efficiency can combine an iS system boiler with one of our iSteel hot water cylinders.

  • Compact dimensions (mm) h700 x w440 x d355
  • Standard 10 year warranty
  • Powered by the unique iCon heat exchanger with a lifetime replacement guarantee
  • Energy-Related products A Rating – the maximum standard rating for heating and hot water
  • Ideal for homes where the heating system includes a hot water storage cylinder
  • Can be combined with ATAG iSteel hot water tanks
  • Can be used with the ATAG ONE controller and 3 port valve kit
  • Completely user friendly

Technical Specifications

Part number BS300332
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) 10
LPG conversion kit available Yes
Solar compatible Yes
NOx class 6
Ingress protection (IP) IPX4D
Maximum equivalent horizontal flue length (m) 60/100mm 9
Maximum equivalent vertical flue length (m) 60/100mm 9
Maximum equivalent horizontal flue length (m) 80/125mm 45
Maximum equivalent vertical flue length (m) 80/125mm 45

Inside the boiler

  1. Gas Valve
  2. Fan assembly
  3. ATAG iCon heat exchanger
  4. Modulating pump
  5. PCB Boiler control unit
Find out what type of boiler you have
"Best decision I made in having it installed. Works efficiently for my family and our requirements"
Mrs Simmons St Albans, Herts