Glow-worm Boiler Reviews 2021

Glow-worm Boiler Reviews 2021

Glow-worm has been established since 1934 and the company still operates from its original base in Derbyshire.

They developed the first cast-iron wall-hung boiler in the 1970s – a huge success for the company – and then they went on to develop many other innovative heating systems before being bought out by Vaillant in 2001.

Their focus on developing compact but energy efficient boiler systems for domestic and commercial use.

If you need a new boiler, you have three options to choose from.

Regular and system boilers both require extra room for their water storage tanks and they can be expensive to fit.

Combi boilers are much smaller, more energy efficient, and cheaper to install and run – this is why experienced installers generally recommended them for most domestic properties in the UK. 

In this review of Glow-worm gas combi boilers in 2021, we’ll cover:

• who Glow-worm is
• what a combi boiler is
• the key stats you need to know about combi boilers and what they mean
• the top 10 Glow-worm boilers according to HomeSage’s exclusive grading guide
• Glow-worm vs other manufacturers – what do customers think?
• Glow-worm’s range of five gas combi boilers up to 27kw
• Glow-worm’s range of five gas combi boilers from 28kw to 34kw
• Glow-worm’s range of three combi boilers with 35kw+ output

It can be tricky to decide on the most suitable boiler for your property so this is why we’ve produced our own exclusive grading system to help you choose.

In this article, we’ve graded each of the top ten gas combi-boilers from Glow-worm according to our unique scoring system. 

We’re HomeSage – we work alongside a network of trusted, established Gas Safe boiler installers up and down the UK.

We help to save you up to 54% on the total cost of the supply and installation of your new boiler – simply fill in a form anywhere on this page.

Once you have sent us your details, we forward these on to boiler installation companies that service your area.

These companies are keen to give you the most competitive quote to win your order and some customers have reported a 54% difference between the highest and lowest quotes, so shopping around is always worthwhile!

Who is Glow-worm?

Glow-worm began life as ‘The Glow-worm Boiler and Fireplace Co Ltd’ in Derbyshire back in 1934 and they used the River Derwent in their early days to transport their products around the country.

They developed many home heating devices throughout the twentieth century and they pioneered the first under-counter boiler – the ‘Hideaway’. 

They merged with The Vaillant Group in 2001 to be a part of Europe’s largest domestic heating group.

In 2005, Glow-worm became the leading manufacturer in the switch to high-efficiency boilers and, within this range, they created the smallest heating appliance which still holds the title for the most compact boiler on the market.

Today, Glow-worm focuses on producing environmentally friendly boilers with a unique market angle of being relatively small but powerful.  

What is a combi boiler?

In today’s modern world, we don’t expect to wait for anything!

This need for instant gratification also applies to our hot water when we turn on the hot tap and when we want the radiators to warm up. 

A combi boiler provides almost instant hot water on demand by heating it directly as it passes through the system from the mains supply.

As opposed to regular or system boilers which store the hot water it dispenses from what are often big and bulky tanks, a combi boiler pipes water directly from the mains through a heat exchanger and onwards onto your hot tap or radiators.

Combi boilers are a wise choice for most UK properties because they are energy efficient, cheaper to install and run, and they don’t take up much space.

They are usually hung on the wall in a kitchen or utility room and they don’t require extra expensive pipework up to a water storage tank in the loft.

There are also many variations of combi boiler available to suit your property size and hot water needs.

Glow-worm currently has 14 different combi boilers available to choose from, all with different benefits and features. 

Why not also check out our article on the best combi boilers on the market in 2021!

Key combi boiler stats

The three key specifications you need to consider for your boiler are the energy efficiency rating, the water flow rate, and the output.

These need to be correct for the size of your home to make sure your energy bills are as low as possible and so that you get the hot water power you desire.

Combi boiler energy efficiency rating

All modern domestic appliances have energy ratings.

Boilers are no different and they are graded by professionals on a scale from ‘A’ to ‘G’ depending on how efficiently they run. 

The more energy efficient a boiler is, the cheaper it will be annually.

This is because a small amount of energy is ‘lost’ to the boiler when it’s switched on meaning it doesn’t go towards heating the water.

It is used by the boiler itself to function but that energy use doesn’t produce any hot water for your taps or your radiators.

For example, if a boiler is 90% efficient, only 10% of the energy is lost.

This would be graded ‘A’ and you would expect your annual heating bill to be considerably lower than from a boiler of grade ‘C’ or below.

Combi boiler output

This refers to how much energy your boiler uses when it’s switched on.

It tells you how much it will cost to run your boiler so this is an important element to consider.

To work out the equation, you multiply the kW amount by the price of a unit of gas.

For example, a boiler of 30kW using gas priced at 4p per unit, it’s 30 x 4p which equals £1.20.

It’s worth nothing that you need to get the right output for the size of your property.

Some properties have boilers with an output too high for their requirements and their owners will actually end up spending more on their gas bills than they need to.

The more hot water you require and amount of radiators you have to heat, the bigger the output will need to be.

For medium sized homes with 3 or 4 bedrooms and up to 15 radiators, a 28-34kW boiler is usually recommended but don’t worry about this yet as we go into more detail on this later on. 

Combi boiler flow rate

As the name suggests, boiler flow rate refers to how much water can flow through the system.

It is measured in one minute so, if a boiler has a flow rate of 11 litres, you can get 11 litres of hot water in one minute.

However, it’s worth remembering that water flow rate is also entirely dependent on how much water you can obtain from your mains supply.

If you can get 10.5 litres per minute from the mains but your boiler allows 15 litres, your maximum water flow rate will still only be 10.5lpm.

Glow-worm’s top ten gas combi boilers

As of 2021, Glow-worm manufactures 14 different gas combi boilers.

Here at HomeSage, we have created a unique scoring system to inform and educate you on your possible boiler options.

There are over 750 boilers on the market today so we want to help you narrow your choices down to find the right one for you.

We base our ranking system on:

• the energy efficiency of the boiler,
• the type of fuel it uses (as gas is the cheapest, these always come top of the list),
• the length of the boiler’s warranty,
• Trustpilot reviews and average score of Glow-worm as a company

Using the HomeSage ranking, our top ten Glow-worm gas combi boilers are:

How does Glow-worm compare with other manufacturers?

As there are a number of reputable boiler companies in the UK, we checked out each of them on Trustpilot to get an overall rating of their services.

Glow-worm finishes fifth for the number of reviews and joint third with Worcester Bosch on their average score.

If a company has more reviews but the same average score, they automatically gain a higher place on our table. Our results are as follows:

What do customers on TrustPilot say about Glow-worm?

Happiness with the product

Most consumers are happy with their experience of Glow-worm with over 78% rating them as ‘excellent’.

They have received 4% ‘bad’ reviews as of June 2020.

Out of over 3,000 reviews, we have highlighted a small selection of recent reviews for your interest:

• On the 24^th June 2020, Marilyn Reed wrote “since our heating engineer installed our new Glow-worm boiler, we have noticed how much more efficient our hot water system is – piping hot water on demand!”

• Dawn Hughes reviewed Glow-worm on the 17^th June 2020 and stated “Old boiler broke Thursday – new boiler fitted and working Saturday. Great!”

• On the 14^th June 2020 Mr Stephen Skilbeck wrote “Thermostat not good. I set the temperature low so it doesn’t come on then the temperature goes back up. The controls on the app are not easy to understand. I want to just use the temperature settings and not the timer. Also, the operating manual is not very user friendly.’

The guarantee period and after-sales service

Glow-worm offers guarantees on their boilers ranging from 3 to 7 years.

They also have the option to extend this to 15 years with Glow-worm’s Club Energy installers.

Their guarantees cover you for both parts and labour as long as the repair is undertaken by a Vaillant Service Engineer. 

Here, we have a selection of recent user reviews on Trustpilot that specifically refer to the after sales service they received from Glow-worm. 

• On the 17^th June 2020, Mr Dan Wood reviewed “being a Registered Gas engineer and fitting these boilers, I fitted a boiler in my own house – great boiler with great warranty and customer service – great reliable boiler.’

• Mr David Hastings reviewed Glow-worm on 13^th June 2020 and wrote “we cannot fault your company. Glow-worm is our first go to boiler company for our installations. Also we think our local rep Barry Urch to be really helpful and co operative. Well done Glow Worm. Kind Regards Dave & Billy Hastings Riverside Heating. Essex.’

• On the 14^th January 2020 Ian Robinson wrote ‘Their boilers may be OK but their customer service doesn’t exist. Have emailed twice with a simple enquiry and they just haven’t bothered to reply! Starting to wonder what will happen if I do have problems with the boiler?’

Glow-worm’s range of gas combi boilers up to 27kw

A boiler with an output of up to 27kW is suitable for a smaller property such as an apartment or a 1 or 2 bed terraced house with under 10 radiators. These boilers are the best choice for properties with 1 bathroom. 

Glow-worm Energy 25kw Boiler (83.14% HomeSage score)

Boilers in the Energy range from Glow-worm feature an aluminium heat exchanger which is designed to be robust and to last a long time.

It has been manufactured to be extra quiet to avoid any distracting noises and, as a result, it has been awarded the ‘Quiet Mark’ accreditation. 

The dimensions of this boiler are 700mm x 390mm x 280mm so, measurements permitting, it would fit snugly within a kitchen unit or cupboard if so desired.

This boiler has a gloss white finish with a silver display panel, digital screen, and a choice of controls.

The warranty for the Energy 25kw is 7-years with the option to extend at an extra cost.

Glow-worm Easicom3 24kw Boiler (3 year warranty) (82.71% HomeSage score)

This model of the Glow-worm Easicom3 24kw comes with a free 3-year out-of-the-box guarantee for parts and labour as long as you follow the warranty rules and regulations provided.

The dimensions of this boiler are 740mm x 418mm x 300mm and it features a traditional white finish with a user-friendly control panel. 

At 94% efficiency, this boiler will bring down your energy costs and you can be safe in the knowledge you are reducing your environmental footprint.

Glow-worm Easicom3 24kw Boiler (6yr warranty) (90.56% HomeSage score)

This is the same model as the Glow-worm Easicom3 24kw but with an extended 6 year warranty.

To activate this deal, you need to download the Glow-worm Plumbing Toolbox app and register with Club Energy.

This one is rated slightly less on the HomeSage evaluation chart because, despite the enhanced warranty, the small premium in price is probably not worth it because of the reliability of Glow-worm boilers.

The dimensions of this boiler are 740mm x 418mm x 300mm and, as with the same model with the lower warranty, it benefits from quiet operation and easy to use settings. 

Glow-worm betacom4 24 Gas Boiler (82.08% HomeSage score)

All of the betacom4 range of Glow-worm boilers include an inbuilt analogue timer and they benefit from compatibility with the full range of Glow-worm remote controls.

The MiGo app makes it easy for you to set your hot water and heating demands on the go for maximum control.

This boiler is 740mm x 418mm x 300mm in dimensions and it’s a nice and modern design. It features a crisp white gloss finish with a contrasting silver control panel from which you can easily program the boiler.

Once you have registered this boiler with Club Energy, you benefit from a 5-year guarantee. 

Glow-worm Essential 24kw Boiler (82.72% HomeSage score)

The Glow-worm Essential 24kw boiler is an effective, reliable boiler high on user friendliness.

As with all Glow-worm boilers, it is compact in size but is packed with useful features.

It measures 740mm x 418mm x 300mm in size and it comes complete with analogue timer and flue in the box.

You receive a free 3-year guarantee with this boiler with the option to extend if you wish.

The Essential range of boilers from Glow-worm provides its users with enhanced energy efficiency through its clever use of lightweight, aluminium components. 

Glow-worm’s range of gas combi boilers with 28-34kw output

Boilers with an output of between 28kW to 34kW suit medium-sized properties like semi-detached homes with up to 4 bedrooms and 15 radiators.

This output level is optimal for homes with 1 to 3 bathrooms, depending on your water usage. 

There are 5 gas combi boilers in this range and the top 5 as ranked by HomeSage are:

Glow-worm Ultimate3 30kw Boiler (85.82% HomeSage score)

The Ultimate3 30kW range of boilers from Glow-worm are best suited to homes with high hot water demands. 

As well as benefiting from £15 cashback when you register with Club Energy, you automatically receive a free 5-year guarantee with this boiler.

It measures in at 740mm x 418mm x 300mm and its features include a Grundfos modulating pump that helps reduce your energy costs, as well as a modern LCD display interface that is ultra-bright for maximum clarity and usability.

Glow-worm Energy 30kw Boiler (83.09% HomeSage score)

One of the latest boilers from Glow-worm, the Energy 30kw is a model developed to be long-lasting, ultra-quiet and easy to install – thanks to a choice of rear or top flue options.

The measurements for this boiler are 700mm x 390mm x 280mm and it features the classic, Glow-worm minimal aesthetic and contrasting chrome control panel. 

It has one of the longer guarantees for Glow-worm as it comes with a 7-year guarantee as standard.

Glow-worm Easicom3 28kw Boiler (82.59% HomeSage score)

A higher output model in the Easicom3 range, the Easicom3 28kw boiler is the same size as its stable mates – 740mm x 418mm x 300mm – but it has a higher output and increased flow rate for those properties needing a little more power and speed.

This boiler is minimal in design and it has a scratch-resistant white gloss shell with an exposed control panel.

The controls are designed to be user-friendly and feature an LED display.

Like all Glow-worm boilers, it is manufactured in their UK factory. 

The Easicom3 28kw uses automotive grade aluminium for the internal heat exchanger which ensures an excellent performance.

Glow-worm betacom4 30kw Gas Boiler (81.98% HomeSage score)

The betacom4 30kW is the next step up from the betacom4 24kW.

It measures the same in dimensions at 740mm x 418mm x 300mm, and it is the hard-working compact boiler you expect from a brand name like Glow-worm.

They have been designed to be compact to fit in with the space-saving requirements of our modern homes without losing style or compromising usability.

The betacom4 30kW benefits from an automotive grade aluminium heat exchanger which makes it light and therefore easy to install and maintain.

This model is compatible with the MiGo heating control app so you can control your hot water needs on the go from your smartphone.

Glow-worm Essential 28 Boiler (78.70% HomeSage score)

The Essential range from Glow-worm offers great value for money for those who need a powerful boiler on a budget.

This model is just shy of the ‘A’ energy rating so you can still expect to save money on your heating costs. 

The dimensions of the Glow-worm Essential 28 boiler are 740mm x 418mm x 300mm and it comes with a 3-year parts and labour guarantee out the box – just make sure you don’t forget to register it online after installation. 

It is compatible with the full range of Glow-worm controls, flues, and accessories to optimise your heating set up and boiler location.

Glow-worm’s range of gas combi boilers with 35kw+ output

Gas combi boilers of 35kW and higher are best suited to large semi-detached or detached homes.

To put it in perspective, a 42kW boiler will run approximately 20 radiators and supply hot water for 3 or more bathrooms so there is no fighting over the hot water.

Here are the top 3 as ranked by HomeSage – please note that there are only 3 boilers whose output is greater than 35kw currently in the Glow-worm range.

Glow-worm Ultimate3 35kw Boiler (85.64% HomeSage score)

The Glow-worm Ultimate3 35kw boiler is a market leader and for good reason.

It provides a high water flow rate with a large output capacity and it is very energy efficient.

This boiler’s dimensions are 740mm x 418mm x 300mm and it features a gloss white finish on the outer shell and a contemporary metallic control panel with a user-friendly interface.

It offers a lengthy guarantee at 10-years once registered and you receive £15 cashback when you register to Club Energy. 

Glow-worm Energy 35kw Boiler (82.81% HomeSage score)

The Energy range from Glow-worm are recent additions to their catalogue and their focus is on ease of use and simple maintenance.

This boiler only requires a simple water flush cleaning for the heat exchanger which means you don’t need to buy special cleaning tools to keep it running.

It is built for longevity as it features a patented 4-sided cooling technology around the heat exchanger.

With this reliability in mind, it comes with a 7-year guarantee out of the box for parts and labour. 

This boiler measures 700mm x 390mm x 280mm.

Unlike the lower output models, the Energy 35kW does not have the ‘Quiet Mark’ accreditation. 

Glow-worm Platinum 40kw Boiler (81.20% HomeSage score)

The Glow-worm Platinum 40kw boiler is also named Energy 35 Store 35 boiler and it is a storage combi-boiler.

This boiler is perfect for large properties whose occupants need the assurance of unlimited instant hot water. 

It combines the benefits of a combi-boiler with the added extra of a storage boiler within a smaller sized unit.

It measures 890mm x 470mm x 561mm but it still has the aesthetics of your traditional wall-hung combi boiler. 

It has a powerful flow rate of almost 20 litres per minute so there’s no worry of losing pressure if numerous people are using hot water at once. 

This boiler comes with a 7-year guarantee with the option to extend at an additional cost for extra peace of mind.

Save up to 54% on your new gas combi boiler

You can save up to 54% of the cost of the supply and the installation of your new boiler by leaving your details with us at any of the forms on this page.

We will contact three or four local, trusted and Gas Safe regulated engineers with your query who will get in touch with you for a free quote and relevant advice.

Our service is completely free for you and it is no obligation – there is no pressure to accept any of the offers from our partner installers if you decide not to go ahead.

Still unsure of what type of boiler, from what manufacturer, is best for you? Why not check out our other post on the best boilers in 2021 or the HomeSage Advice Hub for more info!