Glow-worm Easicom 3 25kW System Gas Boiler | ErP A Rated | 5 Year Warranty
The Glow-worm Easicom 3 25kW System Boiler is one of the most cost-effective ErP A-rated system boilers available from a major UK heating brand. Manufactured in Belper, Derbyshire by Glow-worm — part of the Vaillant Group since 2001 — it brings the engineering standards of one of Europe's largest heating manufacturers to a price point that independent merchants can genuinely compete on.
Sold exclusively through independent merchants in the UK. The package includes the boiler and a standard horizontal flue kit — no need to source the flue separately for a standard installation.
System Boiler Advantages
Unlike a combi, a system boiler works with a separate hot water cylinder to serve multiple bathrooms and showers simultaneously without any drop in pressure or flow rate. All the system components — pump, expansion vessel (8 litres, built-in), and safety devices — are integrated into the boiler itself. No cold water tank required in the loft. This makes it a cleaner, faster installation than a conventional open-vent system, and the preferred choice for homes with four or more occupants or two or more bathrooms.
The Easicom 3 system boiler pairs directly with the Glow-worm HydraCyl cylinder range and is compatible with the full Glow-worm controls ecosystem including MiPro Sense, MiSet, MiGo Select, Climastat Select, and the MiGo Link internet gateway for remote monitoring via the MiGo Xpert installer app.
What Makes This Boiler Worth Specifying
The heat exchanger is aluminium, well-suited to the condensing flow temperatures a system boiler operates at. ErP A-rated at 94% seasonal efficiency, with a PCDB SAP rating of 89.7%. Modulation ratio of 1:5 — the burner turns down to as low as 6.3kW — which means the boiler spends more time running efficiently at partial load rather than short-cycling. NOx Class 5 (39 mg/kWh). Sound power 51 dB(A).
The 5-year warranty is activated by registering through Glow-worm myREWARDS within one month of installation. Installers also earn points through myREWARDS on every registration, redeemable against tools, tech, and training.
Spare parts are available for up to 15 years after production ends, with nationwide stockists at over 500 locations and next-day delivery on emergency orders direct from Glow-worm.
Flue
The Easicom 3 system boiler is a top-exit flue only — it does not have a rear flue option. The standard horizontal flue kit (60/100mm) is included in the pack. Maximum flue length is 9m horizontal or 10m vertical in 60/100mm, and up to 25m in 80/125mm large-bore. Compatible with the full Glow-worm concentric flue range: C13 horizontal, C33 vertical, C53 twin pipe, including the 4-metre single-piece extension unique to the Glow-worm and Vaillant system.
Technical Specification
| G.C. Number | 41-019-49 |
| Manufacturer Part No. | 0010020902 |
| Boiler Type | System |
| Heat Exchanger | Aluminium |
| Max Heat Output | 25 kW (6.0–25.2 kW at 80/60°C) |
| CH Output Range (50/30°C) | 6.3–26.5 kW |
| Seasonal Efficiency (ErP) | 94% — A Rated | SAP 89.7% |
| Modulation Factor | 1:5 |
| NOx (ErP) | 39 mg/kWh — Class 5 |
| Sound Power | 51 dB(A) |
| Fuel | Natural Gas G20 |
| Expansion Vessel | 8 litres (built-in) |
| Pump | Built-in |
| Flue Outlet | Top only |
| Flue Diameter | 60/100mm concentric | 80/125mm available |
| Flue System Types | C13 horizontal, C33 vertical, C53 twin pipe |
| Max Flue Length (60/100mm) | 9m horizontal / 10m vertical |
| Max Flue Length (80/125mm) | 25m |
| Rear Flue | No |
| Dimensions (H x W x D) | 740 x 418 x 300 mm |
| Weight | 32 kg |
| Clearances | Top 205mm | Sides 5mm | Bottom 150mm | Front 600mm |
| IP Rating | IPX4D — Zone 2 bathroom installation permitted |
| Electrical Supply | 230V / 50Hz |
| Warranty | 5 Years via myREWARDS registration |
| Made In | Belper, Derbyshire, UK |
| What's Included | Boiler + standard horizontal flue kit |
Compatible Cylinders
Glow-worm HydraCyl range — 150, 175, 210, and 250 litre capacities. Stainless steel inner tank, 25-year corrosion resistance guarantee when registered via myREWARDS. Coil-in-coil design with reheat times from 14 minutes.
Price Match
Found this boiler at a lower price? Call us on 0118 958 8882 before ordering and we will match any genuine like-for-like UK price. Trade counter collection available same day from Reading (RG1 8JP). Free delivery on orders over £60.
