EFH Electric Flow Heaters


Electric Flow Heater uses electricity as an alternative heat source

The GMS ‘EFH’ range of electric flow heaters have no storage capacity and rely upon circulation of water through the secondary system to dissipate the heat. This enables the design of the flow heaters to be compact with the bore of the shell slightly larger than the immersion heater.


GMS flow heaters are used in various applications, their main use being on closed heating systems such as heating radiator circuits or for space heating requirements. They are also ideal for fresh water applications including swimming pool heaters or as a pre-heat or back up for domestic hot water storage calorifiers. They are an ideal back up service for existing boiler plant permitting boilers to be shut down during maintenance programmes or periods of low demand. They can also be used as a “back up” to main boilers during periods of high demand. The standard range consists of models ranging from 30 kW to 1200 kW, although other outputs can be supplied. Details available on request.


There are several major benefits when using the GMS range of electric flow heaters:

  • Maintenance programmes are minimal compared to that of steam or hot water plants
  • Because flow heaters are compact in their design and do not require separate boilers or fuel tanks, they require minimal room within the plant roomli>
  • Electric flow heaters are clean and efficient method of water heating and do not produce the waste products other sources of power do
  • All the electric power is supplied directly to the immersion heater without any heat loss occurring and all the energy is converted into heat
  • The running costs can be reduced when used during “off peak” tariffs
  • InInstallation is simple. There is no need for primary hot water or steam pipe-work and controls. Only the flow heater has to be installed together with the power supply.
Shell Materials

Flow heater shells for closed circuit heating applications are usually made from carbon steel.The corrosive elements in re-circulated water usually deplete or the water can be treated.Shells on open circuit applications must be able to resist oxidation and be compatible with other components within the system. Most swimming pool applications and domestic hot water systems require shells made in solid copper or stainless steel. When flow heaters are installed into a galvanised system the shell must be galvanised too.

Information Pages


     Some System Considerations

     Ancillary Items

     Thermal Insulation

     Design Standards

Technical Documentation

     Download Data Book

     Download O&M Manual

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