ST (Storage Tank) type electric boilers are sort of a mixture central heating and monothermic type electric boilers. They do not function as instantaneous water heaters but they do keep the water inside an external hot water storage cylinder at a desired temperature. Since domestic hot water (DHW) takes place outside of the electric boiler, in an external hot water storage cylinder, the ST electric boilers do not contain a plate heat exchanger hydroblock. But there is a 3 way valve inside to direct the water towards the external hot water storage cylinder when the water stored inside drops below the set temperature and hysteresis value.

Key Features

• Range rateable (which can improve efficiency rating when utilised).
• Built-in Smart modulator.
• OpenTherm technology, which makes the boiler 15-20% more efficient.
• Economy / energy saving mode.
• Frost protection.