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Boiler brand guides

Glow-worm Boiler Guide

By Matthew Knight

Article 6 of 17

Find out how Glow-worm boilers fared in our latest boiler reliability survey, and what trusted boiler engineers make of Glow-worm.

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

British boiler brand Glow-worm has more than 75 years of experience in the heating business and says it is committed to 'top quality, reliability and exceptional durability'.

Glow-worm has several different gas combi boiler ranges, including Glow-worm Flexicom cxi boilers, Glow-worm Ultracom2 cxi boilers, and Glow-worm Betacom2 and Easicom boilers. It also offers open-vent Ultracom hxi and Flexicom hx boilers, the Ultracom2 and Flexicom sx system boilers and Ultrapower sxi system store boilers. The new Ultimate ranges come with a five-year warranty. 

You can find more details about the individual products in these ranges in our Glow-worm boiler reviews.

Thousands of Which? members take part in our annual survey of boiler brand reliability and customer satisfaction, which enables us to guide you to the best and worst boiler brands. We also conduct a survey with more than 219 Which? Trusted Trader boiler engineers to get their independent views on which boiler brands are the best.

Boiler brand guide
Brand data for Glow-Worm boilers
Overall score M
Customer score
Engineer recommendation
Build quality
Availability of parts and spares
Ease of fixing a common fault
Ease of servicing
Table notes
The reliability and customer score are based on responses from a May 2017 survey of 11,571 Which? members about their boilers. 
Engineer recommendation, build quality, availability of parts and spares, and ease of fixing a common fault and ease of servicing are based on responses to a May 2018 survey of 166 Which? Trusted Traders heating engineers.


Member Content

How much do Glow-worm boilers cost?

Glow-worm boilers cost between £640 and £1,520, depending on the type and size of boiler. 

Choosing the best Glow-worm boiler

The number of years included on the standard Glow-worm warranty varies by boiler range. For warranty protection, either complete and return the warranty form that comes with the box or fill in the warranty form online.

Glow-worm will provide extended warranty packages that last between three and five years.

Glow-worm extended warranties

01773 824639

Glow-worm repairs and spares

Glow-worm has its own team of 200 Gas Safe registered service engineers. 

Boiler breakdown cover is also available from Glow-worm, and there are three levels of cover available.

Boiler breakdown cover quotes

0800 032 7340

Glow-worm spare parts

01773 596020

Glow-worm contact details

You can contact Glow-worm by writing to:

Nottingham Road,
Belper, Derbyshire.
DE56 1JT

or through its website (glow-wormheating.co.uk).

Glow-worm customer service

01773 828 100

Glow-worm technical enquiries

01773 828 300