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The Cheapest 5-Year Guarantee Heat Only Boiler in the UK?

The Cheapest 5-Year Guarantee Heat Only Boiler in the UK?

Buyer's Guide · Heat Only Boilers

The Cheapest 5-Year Guarantee
Heat Only Boiler in the UK?

Meet the Glow-worm Easicom 3 25kW — British Gas heritage, Vaillant Group engineering, and a 5-year warranty at a price that undercuts the market. Exclusively stocked at GetPlumb.

View the Boiler →
Glow-worm Easicom 3 25kW Heat Only Gas Boiler
GetPlumb Lowest Price
£654.79
Glow-worm Easicom 3 · 25kW
Heat Only · 5-Year Guarantee
Buy Now →

If you're searching for a cheap heat only boiler with a long guarantee, you're in the right place. The Glow-worm Easicom 3 25kW is one of the most affordable boilers on the UK market that still carries a full 5-year manufacturer's warranty — and it's backed by the engineering might of the Vaillant Group, one of Europe's most respected heating manufacturers.

Glow-worm Easicom 3 25kW Heat Only Gas Boiler — available at GetPlumb

Glow-worm Easicom 3 — 25kW Heat Only Gas Boiler

£654.79 inc. VAT
  • 5-Year Manufacturer's Guarantee
  • ErP A-Rated · 94% Efficiency
  • Vaillant Group Quality
  • 20% Hydrogen Ready
  • Rear, Horizontal & Vertical Flue Options
  • Fast UK Delivery · Price Match Promise
Buy Now at GetPlumb →

Who Makes Glow-worm Boilers?

Glow-worm is one of Britain's most trusted heating brands, with roots going back over 90 years. Today, Glow-worm is part of the Vaillant Group — the same premium European manufacturer behind the iconic Vaillant boiler range. This means when you buy a Glow-worm, you're getting access to the same rigorous quality control, cutting-edge R&D, and long-term parts availability that premium boiler buyers expect, but at a far more accessible price point.

Think of it this way: Glow-worm is the smart buyer's choice — premium manufacturer, competitive price. The Easicom 3 is the clearest example of this value proposition in action.

Did you know? The Vaillant Group is one of the world's largest heating technology companies, with over 150 years of engineering history. Buying a Glow-worm means you're backed by that same industrial expertise — at a fraction of the premium brand price.

Why Choose a Heat Only Boiler?

Heat only boilers (also known as conventional or regular boilers) are the traditional choice for homes that already have a hot water cylinder and a cold water storage tank in the loft. They are often the best replacement option when:

🏠
Older Heating Systems
Your home already has a traditional vented system with a hot water cylinder — a heat only boiler fits straight in.
🚿
High Hot Water Demand
Multiple bathrooms or large families benefit from a cylinder that stores hot water ready to go, unlike combi boilers that heat on demand.
💰
Lower Upfront Cost
When your existing cylinder and pipework are already in place, a like-for-like swap to a heat only boiler is typically far cheaper to install.
🔧
Simpler Servicing
Heat only boilers have fewer components than combi units, often making annual servicing and repairs more straightforward and less expensive.

Glow-worm Easicom 3 — Key Features

The Easicom 3 is a no-nonsense, high-efficiency heat only boiler designed for straightforward installation and reliable long-term performance. Here's what makes it stand out:

🛡️
5-Year Guarantee
One of the longest warranties available at this price. Full manufacturer's peace of mind from a Vaillant Group brand.
94% ErP A-Rated Efficiency
Energy-efficient condensing technology helps keep running costs low and reduces your carbon footprint year on year.
🌿
20% Hydrogen Ready
Future-proofed for the UK's green energy transition — the Easicom 3 is compatible with up to 20% hydrogen-blended gas.
📐
Compact Design
At just 375 × 280 × 600 mm and 23.5 kg, it's easy to handle and fits neatly in standard boiler cupboards.
🔁
Easy Installation
Designed for simple, quick fitting — saving your engineer time and saving you money on installation costs.
🔙
Rear Flue Option
Supports rear flue exit — a rare feature at this price, giving much greater flexibility for tight or awkward installation positions.
🏅
Vaillant Group Quality
Made to the same exacting standards as Europe's most respected boiler manufacturer — at a British budget price.

Built to a Higher Standard Inside

Glow-worm Easicom 3 internal components — quality engineering inside Inside the Easicom 3 — Vaillant Group engineering quality

Open up the Easicom 3 and you'll find clean, well-organised internals built for longevity and easy servicing. The quality of the heat exchanger, controls, and pipework reflects the Vaillant Group's commitment to reliability — components that are designed to last the full 5-year warranty period and well beyond.

🔙

Rear Flue Capability — Rarely Found at This Price

One of the standout features of the Easicom 3 that often gets overlooked: it supports a rear flue exit. This is a significant advantage that many budget boilers simply don't offer. A rear flue means the boiler can be installed flush against a rear-facing external wall without needing the flue to exit from the side — saving space, reducing pipe runs, and making for a much neater installation. For engineers and homeowners working with tight kitchen or utility cupboard layouts, this flexibility is genuinely valuable and highly unusual at this price point.

Full Technical Specifications

Specification Detail
Warranty 5 Years (Manufacturer)
Output 25 kW
Efficiency Rating ErP A (94%)
Fuel Type Natural Gas
Flue Options Horizontal, Vertical & Rear Exit
Hydrogen Ready Yes — up to 20% blend
Boiler Type Heat Only (Regular / Conventional)
Dimensions (H × W × D) 600 × 375 × 280 mm
Weight 23.5 kg
Colour White
Manufacturer Glow-worm (Vaillant Group)
Part Number 0010020907

The Cheapest Price in the UK — Guaranteed

At GetPlumb, we're confident we offer the cheapest price on the Glow-worm Easicom 3 in the UK. We source directly and pass the savings straight on to our customers — no middlemen, no inflated margins.

🤝

GetPlumb Price Match Promise

Found the Glow-worm Easicom 3 cheaper somewhere else? We'll match it. At GetPlumb, we believe every customer deserves the best possible price on quality heating equipment. Simply contact our team at 0118 958 8882 or email online@getplumb.co.uk and we'll beat or match any legitimate UK price — no hassle, no quibble.

Why Buy From GetPlumb?

🏆
Trade Expertise
We're a UK plumbing and heating specialist — not a generalist retailer. We know these products inside out.
📦
Fast UK Delivery
Orders dispatched quickly with tracked delivery. Boilers typically arrive within 2–7 working days.
📞
Expert Support
Our knowledgeable team is on hand to help you choose the right boiler and accessories for your system.
💳
Secure Checkout
All major payment methods accepted including Visa, Mastercard, PayPal, Google Pay and Apple Pay.

Don't Forget Your Flue Kit

Your Glow-worm Easicom 3 will require a compatible flue to complete the installation. GetPlumb stocks the official Glow-worm flue kits to ensure a perfect, warranty-compliant fit. Choose the right type for your property below:

➡️

Horizontal Flue Kit

The standard choice for most installations. Exits through an external wall — ideal when a rear or side wall is accessible near the boiler.

View Horizontal Flue →
⬆️

Vertical Roof Terminal

The right choice when a wall exit isn't possible. The flue rises vertically through the ceiling and roof — perfect for internal boiler cupboards.

View Vertical Flue →

💡 Not sure which flue you need? Call our expert team on 0118 958 8882 and we'll advise you free of charge.

Frequently Asked Questions

Yes. At GetPlumb's price of £654.79, the Easicom 3 sits among the most affordable heat only boilers in the UK that offer a full 5-year manufacturer's guarantee. Most competing boilers at this price point offer only 1–2 year warranties. You're getting significantly better long-term protection for a budget price.
Absolutely. Glow-worm has been a trusted name in British heating for over 90 years and is now part of the Vaillant Group — one of the world's largest and most respected heating manufacturers. This ownership gives Glow-worm products access to world-class engineering, rigorous quality testing, and long-term parts support that budget-only brands simply can't match.
Yes — and this is a genuinely rare feature at this price point. The Easicom 3 supports rear flue exit in addition to the standard horizontal and vertical options. This means the boiler can be installed flush against a rear external wall with a much neater, shorter flue run. It's a major advantage for kitchens and utility rooms where space is tight or a side exit would be awkward or unsightly.
A combi (combination) boiler heats water on demand and doesn't require a separate hot water cylinder. A heat only boiler (also called a regular or conventional boiler) works with a separate hot water cylinder and cold water storage tank. Heat only boilers are typically the best replacement in older homes with existing cylinder systems, and are preferred in larger homes with high hot water demand.
No, the standard boiler-only package does not include a magnetic filter. However, we strongly recommend adding one when installing any new boiler. A magnetic filter (such as a Fernox or Adey MagnaClean) collects metallic debris from your central heating system, extending the boiler's life and protecting your warranty. Contact our team and we can advise on compatible options.
Yes. The Easicom 3 is compatible with natural gas blended with up to 20% hydrogen. This makes it future-proofed for the UK Government's planned transition to hydrogen-blended gas — meaning you won't need to replace your boiler if the grid moves to a 20% hydrogen blend in the coming years.

The Verdict

The Glow-worm Easicom 3 25kW Heat Only Boiler is a genuinely outstanding deal. You're getting a 5-year warranty, ErP A-rated efficiency, hydrogen-ready technology, rear flue capability, and the manufacturing pedigree of the Vaillant Group — all at one of the lowest prices in the UK market.

Whether you're a homeowner looking to upgrade an ageing system or a heating engineer sourcing a cost-effective, quality-backed solution for a customer, the Easicom 3 delivers exceptional value without compromise.

And with GetPlumb's Price Match Promise, you can buy with total confidence knowing you're getting the best possible price.

🛡️5-Year Warranty
🏆Vaillant Group Brand
💷Price Match Promise
📦Fast UK Delivery
☎️Expert Advice: 0118 958 8882
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