Glow-worm MicraCom Combi Boiler Cost with Installation

The Glow-worm MicraCom is one of the smallest combi boilers available in the UK. At 626mm tall and 270mm deep, it is shorter and around shallower than most standard combis – a difference that opens up installation positions that a 700mm boiler cannot. It uses a stainless steel heat exchanger, a specification more commonly found at higher price points, and LPG versions are available for both outputs. The 5-year standard warranty requires Club Energy registration and annual servicing.

Discover more of the Glow-worm MicraCom combi specifications below:

Glow-worm MicraCom Combi Product Table
	Available outputs	24kW	28kW
	Type	Combi	Combi
	Fuel	Gas	Gas
	Condensing	Yes	Yes
	Efficiency rating (%)	92	93
	ErP	A	A
	LPG compatible	Yes	Yes
	Standard guarantee	5 years
	Max output (kW)	24	28
	Flow rate (l/min)	9.8	11.5
	Mounting	Wall-mounted
	Dimensions (mm)	626 x 400 x 270
	Typical price (incl. VAT)	£600	£700
	Typical installation cost (incl. VAT)	£1,200
	Total cost	£1,800-£1,900

*Terms and conditions apply.

Glow-worm MicraCom Combi overview

Most combi boilers are built to a standard footprint of around 700mm tall, 280-300mm deep, 400-450mm wide. At 626mm tall and 270mm deep, the MicraCom is the solution to installations in narrow wall spaces, low kitchen ceilings, and shallow cupboards.

The fact that it also includes a stainless steel heat exchanger and LPG compatibility is unusual at this price point.

The MicraCom’s stainless steel heat exchanger design makes a real difference in hard water areas where limescale build-up shortens the life of aluminium exchangers over a ten-plus year period.

Glow-worm MicraCom Combi Range
Model output size	House size	Bathrooms	Radiators
24kW	Flats, 1-2 bedrooms	1	Up to 10
28kW	Small homes, 2-3 bedrooms	1	Up to 12

The 24kW model delivers 9.8 l/min, adequate for a flat or small two-bedroom home with a single shower or bath in use at a time. The 28kW reaches 11.5 l/min, more comfortable for a two to three bedroom home with a single bathroom. If you need a boiler suited for two bathrooms in simultaneous use, opt for a bigger combi – you can explore the top picks from our best combi boilers – or a system boiler with a cylinder.

Key benefits at a glance

•       ErP A-rated efficiency, 92% (24kW) / 93% (28kW)

•       One of the shortest combis on the market 

•       Ultra-compact 270mm depth 

•       Stainless steel heat exchanger 

•       LPG compatible

•       5-year standard warranty with Club Energy registration*

•       Large LED display 

•       Removable side panels for front-access servicing

•       Compatible with Glow-worm MiGo smart controls

•       Hydrogen blend ready (up to 20%)

Glow-worm MicraCom Combi technical specifications

The MicraCom is designed around its compact dimensions, a solution for homes where the installation space is smaller and tighter than standard combis would fit. The trade-off is that the MicraCom has a narrower output range and a shorter warranty than larger combis at a similar price. Understanding which of those trade-offs matter for a given property is the key decision.

The stainless steel heat exchanger and LPG compatibility are both unusual inclusions at this price, and they make the MicraCom particularly well-suited to properties with space constraints and hard water – a combination that would otherwise require a significantly more expensive boiler.

Output and efficiency ratings

The 24kW model carries 92% efficiency and the 28kW carries 93% – both within the ErP A-rated band for gas boilers. As condensing boilers, both recover heat from exhaust gases that older non-condensing boilers expelled. 

The high-efficiency pump modulates to system demand, reducing electricity consumption and helping prevent unnecessary cycling on lightly loaded systems.

Dimensions 

At 626mm tall, 400mm wide, and 270mm deep, the MicraCom is significantly smaller than the standard combi on every dimension. 

The 74mm height reduction compared to a 700mm boiler is the primary selling point; the 270mm depth undercuts the Glow-worm Easicom (300mm), the Worcester Bosch Greenstar CDi Compact (280mm), and the majority of compact combis on the market. 

Components included

The MicraCom’s stainless steel heat exchanger is its most significant technical differentiator at this price point. Stainless steel resists the limescale build-up that shortens the life of aluminium exchangers in hard water regions, and its corrosion resistance is a long-term advantage regardless of water hardness. The same exchanger design has been deployed across the Vaillant Group’s range, and is usually only found in more premium combi boilers.

The front panel features a large illuminated LED display with six buttons – a deliberate choice for installations in poorly lit utility cupboards where backlit displays can be difficult to read at a glance. Removable side panels give front access to all components without removing the boiler from the wall, keeping annual service costs lower. The condensate trap is designed for easy removal and cleaning, reducing the risk of winter blockages on exposed condensate pipe routes.

A 1.25m mains cable is included as standard – longer than the 0.75m supplied with most combis – which simplifies connection in installations where the nearest socket is some distance from the mounting position. 

Smart control is available via the optional Glow-worm MiGo Link gateway, sold separately at around £80-£100, which adds remote scheduling and weather compensation via the MiGo app. Third-party thermostats including Hive and Nest are also compatible.

Prices and installation costs

The Glow-worm MicraCom costs approximately £600 for the 24kW and £700 for the 28kW. With installation costs of around £1,200, the total cost of the boiler and installation can cost anywhere between £1,800 and £1,900.

Our prices include a standard horizontal side-wall flue, which routes combustion gases out through an external wall. This is the most common flue type and the most straightforward to install. 

Vertical flues, which some properties will have in place of a side-wall flue, exit through the roof and involve considerably more labour, additional parts, and usually some roofing work; budget £300-£500 extra for a vertical installation on top of the standard horizontal figure.

Using a mid-range installation figure of approximately £1,200:

Glow-worm MicraCom Combi Costs
Output size	Unit cost (incl. flue)	Total (incl. installation)
24kW	£600	£1,800
28kW	£700	£1,900

Warranty and support

The MicraCom comes with a 5-year standard warranty, activated by Club Energy registration within 30 days of installation. Annual servicing by a Gas Safe registered engineer is required to maintain coverage. 

The stainless steel heat exchanger carries an extended component guarantee when registered with Club Energy. 

Installation information

A standard like-for-like combi swap typically costs around £1,200 and can be completed in a day. 

The MicraCom’s compact dimensions make it easier to manoeuvre into tight installation positions than a standard-sized boiler, and the included fittings reduce the number of additional parts an installer needs to bring to site.

What to expect on installation day

Do you need a system flush or filter?

UK Building Regulations require a magnetic filter on any new boiler installation. The filter sits in the pipe and collects iron oxide and metal particles before they reach the heat exchanger.

For the MicraCom’s stainless steel exchanger, which works best in a clean system, it is best to buy a filter from a reputable manufacturer rather than the cheapest available option.

A powerflush of the existing pipework and radiators is separate to the filter requirement and is not legally mandated, but on a system more than ten years old it is the difference between a new boiler performing to its full potential and one working against years of accumulated debris from day one. 

Budget £350-£800 for a powerflush depending on the number of radiators, and £80-£120 for a magnetic filter.

Finding a Gas Safe registered engineer

All gas boiler installations must be carried out by a Gas Safe registered engineer. For LPG installations, confirm the engineer holds LPG certification in addition to Gas Safe registration. 

Use the WhatPrice quote service to be matched with vetted, Gas Safe registered installers in your area.

Reviews and ratings

Glow-worm holds a 4.5 out of 5 rating on Trustpilot UK, based on over 7,000 reviews

Reviews for the MicraCom on Trustpilot are limited, making it difficult to draw firm model-level conclusions; the broader Glow-worm feedback covers service and reliability across the full range.

Positive reviews

A MicraCom review on Trustpilot describes the 24kW as easy to install, very quiet in operation, and straightforward to use – consistent with the broader Glow-worm service feedback, which regularly praises engineer quality and same-visit fault resolution. 

Landlords and installers are the most frequent Glow-worm reviewers, and the MicraCom’s compact dimensions and included fittings pack are noted as practical advantages in tight installation spaces.

Negative reviews

The main MicraCom-specific complaint describes slow heat-up times and inadequate hot water flow when heating and hot water are demanded simultaneously. The reviewer found they could not comfortably run a bath at full flow with the heating on at the same time. This is a characteristic of any combi boiler at the lower end of its output range rather than a fault specific to the MicraCom: when a combi is heating the home and delivering domestic hot water concurrently, domestic hot water takes priority and central heating output is temporarily reduced. 

The 9.8 l/min flow rate of the 24kW model is sized for a single bathroom with moderate demand; properties where this trade-off would be noticeable should consider the 28kW model, or a system boiler with a cylinder if simultaneous demand is a regular requirement.

How the Glow-worm MicraCom Combi compares

Glow-worm MicraCom Combi Comparison Table
Model	Alpha Evoke NX combi	Baxi 400 Combi 2.1 combi	Glow-worm MicraCom
Typical unit price	£800	£800	£600
Heat exchanger	Stainless steel	Stainless steel	Stainless steel
Standard warranty	7 years	5 years	5 years
Max warranty	7 years	5 years	5 years
Built-in WiFi	No	No	No
App control	Alpha Connect (via OpenTherm)	Baxi uSense (sold separately)	MiGo Link (optional)
Cupboard fit	Yes	Yes	Yes
Max output/bathrooms	33kW 1-2 bathrooms	36kW 2 bathrooms	28kW 1 bathroom

For personalised guidance on choosing the right boiler, we recommend speaking with a Gas Safe registered engineer.

Final thoughts – is the Glow-worm MicraCom combi right for you?

If you’re looking for a combi that will fit an unusually tight installation space, then the Glow-worm MicraCom is the right call. Against similarly priced competitors, you’re also getting a durable stainless steel heat exchanger which is rare at such a low cost. In fact, more expensive Glow-worm models such as the Energy combi and Ultimate3 combi have aluminum heat exchangers rather than the durable stainless steel that the MicraCom boasts. Though these combis are backed by longer warranties, support higher hot water flow rates for bigger homes, and have higher energy efficiency ratings which cut costs in the long run – if it is a Glow-worm boiler you’re looking for, it’s worth comparing all their available options and deciding what features matter most to you, before picking one out.

Against its competitors, the Glow-worm MicraCom is around £200 cheaper at £600 – and you’re probably not going to find a combi for less. The Alpha Evoke NX combi and Baxi 400 Combi 2.1 combi sit at around £800 and also host stainless steel heat exchangers, that extra cost reflects the higher output cap compared to the Glow-worm MicraCom which supports homes with two bathrooms. The Alpha Evoke NX combi also has a 7-year warranty compared to the Baxi and Glow-worm options which only go to 5 years.

None of the options at this price bracket have built-in WiFi, but all support optional app control at an additional cost. Ultimately, the right combi for you depends on what your priorities are in looking for a boiler. 

FAQ