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Glow Worm Energy 30c Review

Glow-worm Energy 30c boiler

Looking for a new boiler? If your search is for both an affordable and reliable model, then the Glow Worm Energy 30c might just be the perfect engine for your home. A 30kw boiler, such as the Glow-worm Energy 30C, is sufficient for a three-bedroom standard size house, so if that also fits close to the house size you have, then this could just be the perfect boiler for you!

Are Glow-worm Boilers Any Good?

Firstly, you might want a bit of understanding about Glow Worm the brand. Because, just like when you buy a car, the brand matters. 

Since 1934, Glow-worm has been a leading manufacturer of heating and energy devices in the United Kingdom. This has allowed them to cement themselves within the UK boiler industry, but with the aim of being an affordable and budget boiler brand. 

Simply put, yes Glow Worm boilers are good. However, they are cheaper option, so never expect the same quality as the likes of a Vaillant.

Is Glow Worm a Budget boiler band?

Boilers from Glow Worm are among the most affordable on the market; nevertheless, just because they are inexpensive does not suggest that they are always of inferior quality. However, the saying “you get what you pay for” is a usually a simple truth when it comes to boilers. 

Therefore, you can choose more expensive models and brands, such as the Vailliant Eco Tec plus 835, if you require a boiler with a higher flow rate, more durability, and a bit more firepower.

Short Overview On The Glow-worm Energy 30C

Energy combi boilers Unit 30kW
Boiler dimensions (H x W x D) mm 700 x 390 x 280
DHW flow rate (l/min, 35C rise) l/min 14.2
Maximum horizontal flue length 60/100 m 10
Maximum vertical flue length 60/100 m 10
PCDB seasonal efficiency % 89.2
ErP rating heating A
ErP rating DHW A
Rear flue option Yes
Typical Price £ £1,030.36
Installation Cost £ £500 – £1000

This boiler has an efficiency rating of 89.2 percent, making it an A-rated appliance. The 30 kW output is ideal for medium-sized homes that don’t require a lot of hot water. Whilst also being a wall-mounted, condensing Combi boiler, which makes it ideal for homes with limited space. It’s small enough to fit in a kitchen cupboard, so it’s out of sight when not in use. These are the precise measurements in millimeters: 700 x 390 x 280 millimeters. 

It won’t need an additional water tank or hot-water heater to function correctly. Instead, a single, low-cost machine does it all, heating water on demand while drawing its supply from the water system.

The Pros and Cons

The Glow-worm Energy 30C is a great boiler that is simple to install and operate. The finished product looks neat and clean when hung on the wall. It also has sufficient capacity and is simple to maintain when repairs are required. However, it does have it’s down sides.


  • ErP A rated combi boiler 
  • small enough to fit in most places, even kitchen cupboards.
  • Highly Efficient, which less money spent on running.
  • a wide range of outputs, to meet every need and system requirement: There are models that have 25kW, 30kW, or 35kW of power
  • Rear flue option is available
  • “Quiet Mark” approved because it is so quiet that you won’t even know if it’s on (excludes 35kW model)
  • Low-cost
  • 7-year manufacturer warranty but get Up to 10 years warranty

The Glow-worm Energy 30C has an adequate flow rate of 14.2 liters per minute, sufficient to provide heating for a two- or three-bedroom house. However, when this flow rate is used for hot water, 30.6 kilowatts of power are consumed. This means that it will be enough to provide water for showers and baths for a family of five people.

Because of its modest size, it is also an excellent alternative for people who live in small apartments. This combi heater’s features are more than sufficient for the average individual or couple. Your Glow-worm Club Energy Installer can also provide you with extended warranties of up to ten years.


The Glow-worm Energy 30C is good for small to medium-sized households, however, it may not be sufficient to meet your household’s heating requirements if you have a larger home. 

  • There isn’t enough water flow to use more than two showers at a time. So if you are a big bath lover, you might struggle.
  • Extended warranties of up to 10 years are not automatic and can only be availed if the installation was done by a  Glow-worm Club Energy Installer.
  • Programming the controls might be a tough process at times.

Our Verdict

Glow-worm Energy 30C combi boiler is an excellent choice if you’re looking to replace your current boiler. It’s ideal for tiny houses (and some mid-sized ones), and it comes with everything you need to get the job done, including up to a 10-year manufacturer’s warranty should anything go wrong. However, don’t feel you are going to get much out of it if you have more than two bathrooms and a busy household.

Glow-worm Energy 30c Installation

Contact a gas-safe company to guarantee that the installation is done appropriately. You can feel free to reach out to us at Boiler Choice for an installation, just take out a 60 second online survey to find out what boiler is right for you, or if you are sold on the Glow Worm Energy 30c, give us a call to book in a date for us to carry out the installation. 

Verify that the existing gas meters and pipelines can handle the gas supply rate required to be delivered at their current capacity.

Installation Process

The gas-safe professionals from Boiler Choice will complete the following installation process in accordance with the manufacturer’s specifications. These procedures are carried out in order to ensure the safe and effective operation of your new combi boiler installation.

  1. Flush the heating system –  Before installing open the drain valves on the radiators to allow the tainted water to drain completely from the system.
  2. Do a gas meter check – For safety, verify that the present gas meter can handle the needed gas supply rate. 
  3. Check the gas flow rate –  Measure the gas flow rate at the gas meter and make sure it follows the manufacturer standards found in the manual. Take the gas flow rate at the gas meter and record the results.
  4. Install the gas connection and test for leaks – Check the gas system for any leaks, which can cause serious damage to your boiler and home. Using a maximum pressure of 11 kPa, test the gas valve assembly for leaks. 
  5. Connect the drain pipework for the expansion relief valve – The drain pipes releases hot water so you have to make sure the pipeline is visible. You should make sure that any discharge of water, possibly boiling or steam is kept away from people and wiring to avoid accidents. 
  6. Set up the condensate discharge pipe – Follow the instructions in the manual and observe the local regulations on condensate discharge.
  7. Install the flue pipe – Install and connect the air/flue pipe following the instructions in the manual.
  8. Install the elecricals – Electrical installations will be carried out by licensed electricians. This is done in order to ensure that all electrical installation is safe and adheres to the applicable local code. They will route the connection cables through the grommet provided on the underside of the product on the left . Ensure that the grommet is plugged in correctly and that the cables have been routed correctly.  
  9. Start up and troubleshoot the system – Customers service technicians or qualified persons must perform the initial setup using the Benchmark Checklist.

Detailed instructions can be found in the Installation and Maintenance section of the product manual

In the long run, even if your boiler has been well-maintained, it is more cost-effective to replace it than to keep it. The installation of a modern, more energy-efficient boiler can bring many benefits. 

If you have any questions after reading this, please feel free to contact us. Why not give us a ring at 0800 112 3433 and speak to one of our experts? For those who prefer email, our address is [email protected].