We use cookies to ensure that we give you the best experience on our website and to constantly adjust our website to your needs. We also use cookies to provide you with helpful features and value added functionality. To use the website with full comfort, please accept to receive all cookies on our website.

Accept Decline

Energy combi boilers

ErP A rated small combi boiler

  • Wide range - available in 25, 30 or 35kW outputs
  • Rear flue option
  • High quality, automotive grade, aluminium heat exchanger
  • High efficiency, modulating Grundfos pump
  • ErP A rated for efficiency - helping you to lower your energy bills

Feel the Energy at the heart of your business

Glow-worm’s Energy combi boiler is designed to bring the power of connectivity to you. It’ll connect you to your business, customers, and Glow-worm.

Compact, efficient & high quality boiler range

Designed using automotive grade aluminium, the Energy heat exchanger is a high quality, high efficiency product that makes the boiler light to install. The Energy combi boiler is compact and comes with a rear flue option, making it ideal for a cupboard fit.

The Energy combi boiler comes with a great range of outputs, attractive modern design, bright easy-to-use interface and a choice of controls.

All it requires is simple water flush cleaning for the heat exchanger, which means lower costs and no special cleaning tools. The patented 4 sided cooling reduces the stress on the heat exchanger, which means longer term reliability for your customers. Energy is supported by UK wide spare parts availability.

Work with Plumbing Toolbox for an easier way to install

Club Energy members can use our industry leading Plumbing Toolbox app to make their installations even easier. They can complete the registration, warranty, Gas Safe notification and Benchmark on the go saving a lot of time. Club Energy members are also eligible for rewards on their boilers and can offer their customers up to 15 years of warranty. Find out more about Club Energy here.

Features & benefits

  • Wide product range allows Glow-worm's Energy boiler to cater for every heat output demand and every system requirement
  • Rear flue option gives flexibility to the Energy boiler, meaning it will fit almost all install situations
  • High quality, automotive grade, aluminium heat exchanger designed to last longer, be easy to maintain, is super quiet and reduces customers’ energy bills
  • Offers the choice to install in more locations including a kitchen cupboard
  • Modern, bright, LCD display shows excellent clarity of boiler information wherever it is installed, making it easy to change and confirm settings
  • High efficiency, modulating Grundfos pump resulting in lower running costs as the pump adapts to actual heating and hot water demand



Energy combi boilersUnit25kW30kW35kW
Casing dimensions (H x W x D)mm700 x 390 x 280700 x 390 x 280700 x 390
x 280
Weight (lift)kg323233
CH output minimum/maximumkW5.0/18.36.1/25.47.2/25.6
DHW outputkW25.730.635.7
DHW flow rate (35°C rise)l/min10.412.514.4
Minimum operating pressure (bar)
Minimum pressure for maximum flow
SEDBUK 2009 annual efficiency%89.389.389.2
ErP rating heating AAA
ErP rating DHW AAA
NOx class (natural gas) 555
Heat exchanger materialStainless steel/AluminiumAluminiumAuminiumAluminium
Burner type Downward firingDownward firingDownward firing
Fully modulating YesYesYes
DHW Plate heat exchangerStainless steel/AluminiumStainless steelStainless steelStainless steel
Integrated hydrobloc YesYesYes
Suitable for sealed systems YesYesYes
Filling loop IntegratedIntegratedIntegrated
Inbuilt system bypass YesYesYes
Inbuilt condensate trap/siphon YesYesYes
Inbuilt frost protection Yes YesYes
Zero compartment ventilation YesYes Yes
Pump type GrundfosGrundfosGrundfos
User interface
Diagnostics Advanced/IntuitiveAdvanced/IntuitiveAdvanced/Intuitive
User adjustable CH temperature control YesYesYes
User adjustable DHW temperature control YesYesYes
Warm start function YesYesYes
Optional spacing frame - 0020193660 YesYesYes
Plug in mechanical timer - 0020095196 OptionalOptionalOptional
Aesthetic pipe cover - 0020193659 YesYesYes
Optiflue compatible (PEGHRD) - 0020152034 YesYesYes
Maximum horizontal Ø60/100m101010
Maximum vertical Ø60/100m101010
Maximum horizontal Ø80/125m252525
Maximum vertical Ø80/125m252525
Optional plume management kit Ø60/100 YesYesYes
Direct rear flue optionYes/NoYesYesYes

*See manual for clearance if side panels are to be removed to assist future service and maintenance

**5mm if removable panel/door

Related Products

Related Products

Introducing MiGo

The personal heating assistant

  • Wi-Fi thermostat and easy-to-use app
  • Manage heating and hot water from anywhere
  • Reduces energy consumption, saves money
  • Internet weather compensation
  • eBUS communication

Climapro₂ RF Control

Climapro₂ RF

  • Two channel wireless programmable room thermostat
  • Backlit display provides advanced user control and functionality
  • Capable of room and weather compensation*
  • Simple to use handheld unit



Alternative products

Alternative products

Ultimate₂ combi boiler

Exclusive combi boiler with 5 years warranty*

  • Leading combi boiler offering great performance
  • FREE 5 year warranty* with option to extend
  • £15 reward when registered through Club Energy
  • Available in 30kW and 35kW models