Glow-Worm Ultimate3 Combi

Glow-worm, a UK-based boiler company with over 80 years of boiler production under it’s belt, is now a part of Vaillant, the world-renowned heating company. Glow-worm manufactures all of its boilers at its state-of-the-art production facilities in Belper, Derbyshire. With a focus on producing reliable and highly efficient products, Glow-worm is a brand you can trust. 

The Ultimate3 Combi is a highly efficient gas condensing boiler from Glow-worm. It is a compact yet powerful combi boiler that comes with some brilliant additional features you won’t see in similar models. If you are considering the Ultimate3Combi as your new combi boiler, read ahead for the answers to all of your questions. We have done all the research and have all the information you may need to see if the UltimateCombi is the right boiler for your home.

How Much Does The Ultimate3 Combi Cost?

The UltimateCombi from Glow-worm comes in two different power outputs; 30kW or 35kW. Therefore, the price of the boiler will depend on which power output your home needs. The smaller, 30kW version should cost around £700, while the 35kW around £775. 

It is important to note that this price, although including VAT, doesn’t include the installation costs. These installation costs are usually hefty enough, costing up to £1,500. Always remember to take this additional cost into consideration. 

Is This Boiler Suitable for My Home?

Combi boilers are usually only recommended for smaller homes, as they do not work with hot water cylinders so they usually struggle with the hot water demands of larger homes. However, the UltimateCombi is a powerful combi boiler, suited to medium to large homes, with one or two bathrooms. 

This is a general guide. It is essential to get your home checked by a heating engineer, as they can monitor your hot water and central heating usage and be able to recommend a suitable boiler for your home. 

One thing that’s for sure is that the UltimateCombi is a brilliant option for homes lacking storage space. The boiler itself is small, and it does not require any additional water storage tanks. This is a great bonus and helps to create more space in homes with limited storage space. 

Replace Your Existing Boiler With Glow-worm’s Ultimate3 Combi

No matter what heating system you have in place already, replacing your old boiler with the UltimateCombi should be a breeze. If you have a combi system already in place, this combi boiler will slot right in easily. If you have a system or regular heating system in place, congratulations, you have just gained more storage space in your home, time to get rid of those bulky water tanks! 

The UltimateCombi is a relatively small unit and will fit comfortably in a larger storage cupboard. It also comes with a wide range of flue options, which adds endless possibilities to where it can be stored in the home. The boiler is exceptionally light at 22kg, which means your installer will be easily able to maneuver it into tight, awkward spaces. 

Boiler Energy Efficiency

For the environmentally conscious, the most important thing to consider when buying a new boiler is energy efficiency. In fact, it is something that we should all be aware of so that we can do our bit for the planet. However, while a highly energy-efficient boiler will shrink your carbon emissions, it has another benefit; a considerable reduction in your gas bill. 

The UltimateCombi is a highly efficient boiler. It boasts an ErP energy-efficiency rating of 94%, and when combined with Glow-worm’s smart heating controls like the MiGo personal heating assistant, this efficiency can be increased even further. 

The Ultimatecomes with a brilliant high-efficiency feature; the Grundfos modulating heat pump. This heat pump automatically adjusts to your home’s energy needs, increasing the boiler’s efficiency and lowering the boiler’s running costs. 

Ultimate3 Combi Controls & Features

The UltimateCombi is very user friendly, with a clear, bright LCD display where the settings can be easily monitored even in dimly lit areas. The boiler comes with the usual controls you would expect; an on/off button, temperature control switches and a reset button. 

This combi boiler can be combined with a wide range of accessories to enhance the user experience and increase the boiler’s efficiency. These accessories include the MiGo personal heating assistant, the Climapro2 RF Control. 

How Long Is The Warranty On This Boiler?

This combi boiler from Glow-worm comes with a standard 5-year parts and labour warranty. However, this can be extended to a whopper 10-year warranty when a Club Energy registered installer installs the boiler. 

The warranty will cover the cost of any ‘parts’ which need to be replaced and the ‘labour’ costs of calling out an engineer to make repairs. You must follow the terms and conditions to avail of the full benefits of this warranty. These terms and conditions include the boiler’s yearly service, a part of good boiler maintenance anyway. 

Ultimate3 Combi By Size & Price

The UltimateCombi certainly isn’t the smallest boiler on the market. Unfortunately, it won’t fit in your standard kitchen cupboard like other combi boilers. It’s dimensions are; 740 mm (H) x 418 mm (W) x 300 mm (D). This means it can fit in a larger storage cupboard. 

Features & Benefits

The UltimateCombi comes with some brilliant features, making this boiler one of the best combi budget combi boilers on the market. Read ahead for a quick look at the UltimateCombi’s best features; 

Grundfos Modulating Heat PumpMaximises efficiency and reduces running costs. 
Aluminium Heat Exchanger Improves boiler performance and prolongs the life of the boiler. 
Inbuilt Filling Loop Easy maintenance.
Highly EfficientCut down on your carbon emissions and your gas bill. 

These features make it clear to see that this combi boiler has been designed around reliability and efficiency. The high-quality automotive-grade aluminium heat exchanger enhances the boiler’s performance while prolonging the life of the boiler. 

The inbuilt filling loop will help you save money on maintenance fees by avoiding unnecessary engineer call-outs. These features all add to the efficiency and reliability of this powerful combi boiler.

Smart Heating Controls

Smart heating controls are one of the best innovations to happen in the boiler manufacturing industry. These smart heating controls can connect your smartphone to your boiler through a smart thermostat. This allows the homeowner complete control over their home heating system on the go. 

Glow-worm has its own smart heating app called MiGo. This app can significantly enhance your boiler’s efficiency as it learns your homes energy needs. Not only will this save you money on your gas bill, but it will also save you stressing about energy wastage in your home. 

Does The Ultimate3 Combi Work With Google Nest?

Yes, the UltimateCombi can work with Nest, the smart thermostat from Google. Nest allows the homeowner to control their home heating system on the go. 

Does The Ultimate3 Combi Work With Hive?

Yes, the smart thermostat Hive can be used with the UltimateCombi. This smart thermostat can learn your home’s energy needs and create an optimised heating programme for your home. 

Does The Ultimate3 Combi Work With Tado?

Yes, the smart thermostat Tado can be combined with the UltimateCombi in order to optimise the boiler’s performance and maximise efficiency.

Is the Ultimate3 Combi Any Good?

Yes, the UltimateCombi is a brilliant budget boiler suitable for small to medium homes. It has some excellent features which help to make the boiler a highly efficient model. It is stylish and compact, fitting into more spacious storage cupboards. With no need for water storage tanks, it is an excellent boiler option for homes with limited storage space. 

Pros and Cons

Before deciding if the UltimateCombi is the right new boiler for your home, read ahead for a quick summary of the pros and cons of this boiler.


The pros of the UltimateCombi boiler; 

  • Highly energy-efficient; reduce your carbon emissions while saving on your gas bill. 
  • Aluminium Heat Exchanger; maximises boiler performance and ensures the longevity of the boiler. 
  • Option of a 10-year warranty; security and peace of mind with this investment. 
  • Compatibility with smart heating controls; increase your boiler’s efficiency. 
  • Grundfos modulating heat pump; reduce energy wastage in your home.


Despite the numerous pros of the UltimateCombi, it is essential to acknowledge its cons; 

  • It is slightly bigger than most combi boilers, meaning it cannot be stored in handy storage places such as a kitchen cupboard. 

Is Boiler Finance Available?

Yes, boiler finance is available without an issue. The interest rates for boilers like the UltimateCombi are generally very low.

Do I Need Boiler Cover?

Yes, although boiler cover may seem like an unnecessary additional cost, it can save you a lot of money in the unlikely event that you will need to replace part or all of your boiler.