Our website uses cookies to help provide you with the best experience tailored to your interests. To use the website with full comfort, please accept to receive all cookies on our website. For more information with regard to Cookies please see our Privacy policy.

Accept Decline

Ultimate₃ combi boilers

High efficiency combi boiler from Glow-worm

  • Leading combi boiler offering outstanding performance
  • ErP A rated for efficiency – helping you to reduce your energy bills
  • FREE 5 year parts and labour guarantee
  • Extended guarantee options available
  • Our 30kW and 35kW models suit homes of all sizes
Find your local Glow-worm Club Energy installer

Outstanding performance

The Ultimate₃ combi boiler provides central heating and hot water without the need for a cylinder or tank to store water. The Ultimate₃ combi is available in a choice of 30kW and 35kW models making it suitable for a range of homes, and provides a high domestic hot water flow rate to ensure reliable performance for you and your family.

Built with an automotive, grade aluminium heat exchanger, the Ultimate₃ is designed to offer high performance. The Grundfos modulating pump also helps to reduce energy use meaning the boiler is ErP A rated when it comes to efficiency.

The boiler features a modern, bright, LCD display with an easy-to-use interface, and is also compatible with Glow-worm’s popular MiGo app based control (sold separately). This means you can control your heating and hot water from anywhere at anytime by simply using your mobile phone or tablet.

The Ultimate₃ also comes prepared with a 10 year parts and labour guarantee when your Gas Safe registered installer registers the installation on the Glow-worm Club Energy installer loyalty programme.

Features & benefits

  • Combi boiler range with a choice of 30 or 35 kW outputs
  • Modern, bright, LCD display with easy-to-use interface
  • High quality, automotive grade, aluminium heat exchanger providing excellent performance
  • High efficiency, A rated boiler for ErP energy labelling to reduce energy bills
  • Grundfos modulating pump for further reduced energy use
  • Inbuilt filling loop for straightforward maintenance
  • Compatible with a full range of Glow-worm controls, flues and accessories
  • Ideal for use with the innovative MiGo app based control
  • 5 years parts and labour guarantee with option to extend*
  • Wide range of compatible flue options available
  • Wide range of Glow-worm accessories available

*When registered through Club Energy



Ultimate₃ combi boiler30kW35kW
Boiler dimensions
(H x W x D mm)
740 x 418 x 300740 x 418 x 300
DHW flow rate storage/combi (35°C rise) (l/min)12.414.4
Maximum horizontal flue length 60/100 (m)106
Maximum vertical flue length 60/100 (m)1010
PCDB seasonal efficiency (%)89.689.7
ErP rating heatingAA
ErP rating DHWAA

Related Products

Related Products

MiGo personal heating assistant

  • Remote heating and hot water control
  • Automatically learns your energy needs
  • MiGo and Glow-worm boilers speak the same language

Climapro₂ RF Control

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


  • Easy to use
  • Extra low voltage
  • Simple & discreet 2 wire connection



How to get

Want to find out more?

Find your local Glow-worm Club Energy installer

Club Energy is Glow-worm’s installer loyalty scheme. By choosing a Glow-worm Club Energy Partner, you’re choosing our network of fully trained, independent installers who can offer you exclusive extended Guarantees, as well as a free no obligation quote to ensure your Glow-worm boiler is the perfect fit for you and your home.

Alternative products

Alternative products

Ultimate₃ system boiler

  • Highly reliable system boiler offering outstanding performance
  • ErP A rated for efficiency – helping you to save money on your energy bills
  • FREE 5 year parts and labour guarantee*

Ultimate₃ regular (open vent) boiler

  • High performance, ErP A rated regular boiler
  • Lightweight boiler with cupboard fit dimensions
  • FREE 5 year guarantee*

Energy combi boilers

  • ErP A rated for efficiency - helping you to reduce your energy bills
  • Compact size will fit in kitchen cupboards
  • Highly efficient for lower running costs