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Glow-worm Ultimate3 System

Glow-worm is a well-known central heating system on the market. You may have seen it alongside Worcester Bosch, Baxi, Vaillant, and Potterton.

You may have also heard of the Glow-worm Ultimate3 system gas boiler, but is it a combi boiler you need or a system boiler, both are available in this range. Glow-worm Ultimate3 System Compare Boiler Quotes

In the boiler guide below, we will tell you all the critical information about the Glow-worm Ultimate3 System Gas system boiler.

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Boiler Cost:

Quite often, the first thing you would think about with your boiler is the price. Boilers are often much cheaper than your first thought.

Companies like Boiler Central offer to have your boiler fitted before you pay a penny! Glow-worm Ultimate3 System Compare Boiler Quotes

Click the link here to see this offer 

Replacing your old inefficient boiler to a modern, efficient boiler will be a significant saving within your fuel bills, sometimes saving over £300 a year.

This 25kW output system boiler would cost around £800, ensure to check the boiler includes VAT.

Boilers do not usually include installation fees, which would be an extra cost. Boiler installation can cost up to £2000.

If you would prefer your boiler to include installation fees, go to 


Is this Boiler Suitable for My Home:

A system boiler would be recommended for old traditional homes rather than new builds.

System boilers also are known as Regular or Traditional boilers. Going by the name “Traditional,” back in the day homes, a hot water storage cylinder was designed to live in the airing cupboard, the cold water tank to live in the loft, and the main unit to live in a kitchen cupboard. 

You are probably gathering now that a System boiler takes up a lot of extra space. Glow-worm Ultimate3 System Compare Boiler Quotes

High-performance System boilers are excellent for larger homes that demand water to more than one tap at once.

This 25kW system boiler would be perfect for a home with up to five bedrooms and multiple bathrooms.

Your Gas Safe approved boiler engineer will make the final decision whether this is the best-rated boiler to run your home.


Is this a High-Efficiency Boiler:

The answer to this question is Yes.

The efficiency rating for this boiler is over 90% and has an A rating. Glow-worm Ultimate3 System Compare Boiler Quotes

Controls can also be attached to this boiler to enhance efficiency to the maximum.

The boiler has a Grundfos modulating pump built within, the job for this pump is to reduce energy and memorise how much energy you use.



We said before this boiler has an ErP A rating and that controls can be used to enhance this performance to the maximum so that we will take a look at this here.

The boiler has an automotive-grade aluminium heat exchanger built within to enhance the performance and to lengthen the life of the boiler. Glow-worm Ultimate3 System Compare Boiler Quotes

An inbuilt filling loop has been included to ensure maintenance is simple. A bright LCD display with an interface that is simple to use is attached and built within is the Grundfos pump to save energy wastage and lower the energy bills.

A trendy accessory that can be added on is the MiGo App. This app allows you to control your heating and hot water system wherever you are off your smartphone and tablet. The app also memorises your requirements.



This boiler comes with a standard five-year warranty for parts and labour.

Warranty is always great for peace of mind in case any issues occur. Glow-worm Ultimate3 System Compare Boiler Quotes

Always follow the website guidelines to keep your warranty valid.



Glow-worm Ultimate3 Model & Price:

Ultimate3 System 25 System H – 740 mm
W – 418 mm
D – 300 mm
N/A 25 kW 90% AND ABOVE £810


Advantages & Disadvantages:

Below, you can see the advantages and disadvantages of the Glow-worm Ultimate3 System:


  • Suitable for homes with up to five bedrooms and multiple bathrooms.
  • Simple to install, service, and control.
  • Grundfos pump has been built within to lower the fuel bills by reducing energy use.
  • Top-quality parts have been used to help the performance and lengthen the life of the boiler. Components such as – A High-grade aluminium heat exchanger.
  • Environmentally friendly.  Glow-worm Ultimate3 System Compare Boiler Quotes
  • Fits with various controls to reach maximum efficiency.
  • The MiGo app can be used to control your central heating wherever you are.
  • A decent warranty for five-years is standard for parts and labour.
  • Can run water to more than one tap with no issue.


  • Which? Give Glow-worm an overall score of 54%
  • System boilers take up extra space with the hot water cylinder and cold water tank.

If you would like a boiler quote or any information click here 

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What our customers think

5 Stars on Trustpilot

Would recommend

Stressed when needed a new boiler but easy process with affordable finance. New boiler installed within a few days with option for next day.

Paul Jones 5 Star on Trustpilot

We were very impressed

On the day, they came on time. Lovely people, they kept everything clean. Explained everything to me. No mess, kept me informed.

Anne Cross 5 Star on Trustpilot

Great Experience

Great experience - quick to arrange, easy to work with the very responsive online team and all installed faster than expected.

Ms Baxter 5 Star on Trustpilot

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