A hastily put together team of anthropologists are currently working night and day to find out why Glow-worm boilers are actually named, Glow-worm. In the meantime, scan over our snippet of Glow-Worm boiler reviews.
Want to know more about the Glow Worm brand and the boilers they offer? And ultimately are Glow Worm boilers any good?
Owned by industry leader Vaillant, Glow Worm is a popular boiler brand in the UK, but how do they compare?
In the following review of the brand, we’ll look at the various offerings from the manufacturer and their prices.
We'll also break down how Glow Worm compares with its rivals, among other key facts anyone considering a Glow Worm boiler should be aware of before making a final decision.
We chose not to fit Glow-Worms because we didn’t find them all that funny. But we can quote for some top-end boilers instead.
History of Glow Worm
Glow Worm prides itself on being a pioneer in British domestic heating for nearly 90 years with the manufacturer having first produced boilers in Derbyshire in the mid-1930s.
Since then, Glow Worm has produced a wide range of boilers and continues to do so at their high-end manufacturing facilities located in Belper, Derbyshire.
Their range includes combi boilers, system boilers, and regular boilers.
A British brand, crawling the Earth for around nearly 90 years
Returning to their history, Glow-worm was acquired by the second-largest heating company in Europe, the Vaillant Group, at the turn of the century.
Vaillant is an employer of more than 12,000 people throughout Europe and Asia and remains in control of Glow Worm to the present date. Vaillant provides ventilation, A/C, and heating technology to 100,000s households across the globe.
Glow Worm Gas Boilers
Glow Worm gas combi boilers are one of the most efficient and convenient types of boilers you can use. Combination (or combi boilers) are by far the most common type of boiler in the UK, installed and used in as many as 70% of homes.
Modern A-rated combi boilers offer over 90% efficiency and provide both on-demand hot water, and heating in one compact unit.
This means that unlike other types of boilers e.g. system and regular, you do not need to use or have a separate hot water storage tank installed, helping to save space and make installation easier.
It also means you don’t have to worry about the hot water running out within the storage tank, which is of course a limited amount of water and not provided on-demand, like a modern combi boiler.
Glow Worm Combi Boiler Prices
The brand has a wide choice of boilers to choose from including a great selection of combination boilers. There are 30 Glow Worm combi boiler products in total.
For the models listed below, we will look at specific model ranges which generally comprise 2-3 specific products although in some cases we will list single product ranges.
It should be noted that a higher boiler output does not always correspond with a higher price tag.
Glow worm sit towards the budget end of the boiler spectrum, competing with the likes of the fantastic Alpha E-Tec.
These combi boilers are perfect for households with a low to moderate need for a hot water/central heating system (CHS).
The combi boiler models with an output of between 24 kW and 27 kW are best suited to homes with up to ten radiators.
As with any type of boiler, you’ll want to carefully consider the output among other factors before choosing the right boiler for your property.
Glow Worm Combi Boiler Ranges
Models | kW | Warranty | Product Price | Overall Price (including installation) |
Energy Combi Gas Boilers | 18-25 | 7 years | £775 to £915 | £1,775 to £2,215 |
Betacom4 Combi Gas Boilers | 21.2-30 | 5 years | £525 to £565 | £1,725 to £1,965 |
Easicom3 Combi Gas Boilers | 24-28 | 3 years | £614 to £665 | £1,814 to £2,265 |
Ultimate3 Combi Gas Boilers | 30-35 | 5-10 years | £705 to £775 | £1,805 to £2,075 |
Easicom3 Combi Gas Boilers | 24-28 | 3 years | £625* | £1,725 to £1,925* |
Compact Combi Boilers | 24-28 | 5 years | £598 to £706 | £1,998 to £2,706 |
Compact Combi LPG Boilers | 24-28 (LPG) | 5 years | £598 to £706 | £2,098 to £2,406 |
Energy LPG Combi Boiler | 30 | 10 years | £988 | £2,487 to £2,588 |
Glow Worm System Boiler Prices
Moving on to the brand’s system boilers, we’ll lay out the prices in the same manner as we did in the previous section. Glow Worm offers eight system boilers altogether.
Since system boilers can directly heat your CHS while simultaneously keeping hot water in cylindrical storage, they are better suited to properties with higher hot water demands than combination boilers.
A Glow-worm system boiler is a good choice if your home features several bathrooms.
Similar to combi boilers, they heat water from the mains water supply but instead of diverting it directly to water outlets e.g. taps, baths or showers, it is stored in a hot water tank.
Looking to pay for your new boiler monthly? Refer to our boiler on finance guide for more info.
Glow Worm gas system boiler ranges
Models | kW | Warranty | Product Price | Overall Price (including installation) |
Energy System Gas Boilers | 12-30 | 7 years | £700 to £850 | £1,800 to £2,150 |
Ultimate3 25kW System Gas Boiler | 25 | 5 years | £725 | £1,825 to £2,225 |
Easicom3 25s System Gas Boiler | 25 | 3 years | £595 | £1,995 to £2,695 |
Glow Worm Regular Boiler Prices
We’ll now look at the price range for Glow Worm’s regular or open vent boilers.
Another name for these boilers is heat-only boilers. Glow Worm offers eleven open vent boilers in total.
These appliances are the more traditional option. Notably, they must be fitted along with a cold-water storage tank, hot water cylinder, and expansion vessel.
The Glow-worm open vent boilers with a 25kW output are perfect if your household has 10-15 radiators.
Glow Worm Regular Boiler Ranges
Models | kW | Warranty | Product Price | Overall Price (including installation) |
Easicom3 Regular Gas Boiler | 25 | 3 years | £685 | £1,985 to £2,100 |
Energy Regular Gas Boilers | 12-30 | 7 years | £713 to £890 | £2,113 to £2,390 |
Ultimate3 25kW Regular Gas Boiler | 25 | 5 years | £725 | £2,525 to £2,825 |
Glow Worm Warranty/Guarantees
A boiler warranty is an essential factor when buying any new boiler for your home as you want to be confident that in the event the boiler breaks down, it will be repaired and up and running as soon as possible, ideally for free.
As far as guarantees go, Glow Worm’s guarantees range from three to ten years, depending on the boiler in question.
Here’s how their guarantees work:
Glow-worm guarantees cover repairs of any defects related to the manufacture of the appliance.
The repair must be completed by a Vaillant Service engineer with the guarantee covering the labour and materials.
The guarantee will not cover defects unrelated to the manufacture of the boiler.
The guarantee will also not cover defects that have been the result of misuse.
Once the boiler is installed, remember that you’ll need to register your Glow Worm guarantee. You should do this within 30 days of the boiler being installed to make certain you’re covered.
You may be able to avail of exclusive extended warranties (up to a decade) via your Glow-worm Club Energy Installer.
Unfortunately, the Glow Worm warranty isn't the best, especially when you start to compare it to other boiler manufacturers' warranty offerings.
For example, a boiler guarantee offered with Worcester Bosch boilers is 10 years (when purchased via Heatable).
Glow Worm Customer Reviews
What do customers think of Glow Worm? Nothing quite compares to the honesty and feedback from everyday users of the product and aftercare.
The good news is that Glow Worm has a superb score on Trustpilot. As of July 2024, over 6,944 customers left a review.
The brand has an average rating of 4.6 stars out of 5, which is excellent for a company selling boilers in such large volumes.
Glow Worm Awards & Accolades
Glow Worm boilers don't currently hold any awards for their gas combi boilers, however, in 2018, the brand was awarded the Which? Best Buy Award.
The consumer organisation Which? conducts an annual boiler survey of 7,500 customers and 150 of its trusted heating and plumbing engineers, asking them key questions about reliability, customer service and servicing.
In the 2018 survey, Glow Worm was the only boiler brand to be awarded three stars from engineers for all categories, except the availability of spares and parts, for which they were awarded 4 stars.
The 2024 model is largely unchanged from its 2018, award winning predecessor.
Check our new boiler costs guide and use our boiler size calculator if you want to get a better understanding of how our fixed price boiler quote tool works.
Glow Worm vs the Competition
Having looked at the various boilers offered by Glow-worm, let’s explore how the manufacturer compares with its rivals.
The key competitions of Glowworm are Ideal Logic Plus and Worcester Bosch, both of which are also British manufacturers.
Each of these rivals sells similarly priced products to Glow-worm and offers comparable warranty packages.
While Glowworm has a long history, they aren’t the most innovative brand. However, the ability of Glow-worm boilers to process water (in terms of volume) is at the top of the market.
Glow Worm boiler displaying the F75 fault code? Find out how to fix it here.
For example, the Glow-worm Ultimate 3 Combi Gas Boilers have output ratings of 30-35 kW. Clearly, Glow-worm is a solid brand, and its boilers are worthy of serious consideration.
Glow Worm Key Facts
Now that you’re aware of the price ranges of Glow-worm boilers and how the brand compares with its competitors, let’s look at other useful information related to Glow-worm.
Glow Worm Repairs and Servicing
First and foremost, Glow Worm can meet your annual boiler servicing needs. Glow-worm servicing involves an expert engineer performing a rigorous 12-point boiler check.
Their engineers are factory trained in-house. Glow-worm offers a boiler service for as low as £120.
Glow-worm also provides a fixed price one-off boiler repair. All their repair services come with a free gas safety check.
However, it should be noted that if the boiler is beyond economical repair, Glow-worm will not be able to repair your boiler as part of their fixed-price repair package, however, you’d still only face a fee of £99 to cover the labour cost. Should this happen, Glow-worm will advise you as to an appropriate replacement boiler.
Their engineers can offer a one-off boiler repair for boilers no longer under guarantee. If your boiler is still within the guarantee period, call them on 0330 100 3150 to have your boiler fixed.
Quiet Mark Approved
Glow-worm’s Energy range is Quiet Mark approved. This infers that the boilers are deemed to be ultra-quiet. The range is essentially recognized for excellence in quiet product design.
Glow Worm Controls
One of the most notable advantages of Glow Worm is there a wide range of heating controls, that enable you to take more control of your heating, enabling you to reduce energy waste and save money on your heating bills.
For example, the Glow Worm Wireless Outdoor Sensor is able to sense the outdoor temperature to enable weather compensation for maximum efficiency.
The best part is it doesn't require any batteries or wiring either, instead, it's powered by indirect sunlight which recharges the small PV cells.
You also have the option of using one of the leading smart thermostats, such as the Google Nest or Hive.
Glow Worm Error Codes
Just like other boiler manufacturers, Glow Worm has built-in error codes that indicate and help diagnose certain boiler problems.
For example, the Glow Worm F28 error code can indicate a failed or faulty boiler ignition.
Glow Worm Boilers Verdict
Glow Worm is a relatively popular boiler brand in the UK with a wide selection of boilers, including combi, regular and system boilers.
They are also available in a wide variety of different sizes/power outputs, so you will easily be able to acquire one that will meet your home’s hot water demands.
However, having said that, we would probably recommend a different boiler brand, you can see how we ranked the UK’s most popular boiler manufacturers in our best boiler brands guide.
Viessmann ranked number one, while Alpha ranked number two, so we would advise a boiler from one of these two brands before a Glow Worm boiler.
We have also reviewed and compared many other popular UK boiler brands, including the following:
Time for a new boiler?
If you chop a Glow-Worm boiler in half, unfortunately, you will not have two independently thriving worms.
You may need a new boiler.
You may need it fast, and with affordable monthly payments.
You may even need it from a company with top end local engineers, with 10,000 Trust Pilot reviews to back them up. Plus a Which? Trusted Trader award for good measure.
You may need a new boiler quote from us, Heatable 😘
