Grant developed the first oil-fired external boiler in 1986 and although the concept was new to the oil market, it quite quickly became a popular addition to Grant's boiler range. It is therefore appropriate that Grant has taken the lead with three Eco external modules, available in outputs between 15 kW and 35 kW.

• Whisper quiet
• Optional pipe entry points
• Frost stat set to 5C (factory fitted inside control panel)
• Condensate trap (factory-fitted in rear)
• Riello RDB burner (with plug and socket connection)
• Efficiency of 90.3% to 90.8% Gross (SAP2009)
• 1 Year standard Warranty and 2 years if registered within 30 days
• Extended to 5 years if installed by a registered G1 installer with a Grant or equivalent filter