Alpha E-Tec 20 NXS System Boiler

Price: £952 each, inc. VAT | Ex. installation | 3-10 years boiler finance available.

The Alpha system boiler; the E-Tec 20 NXS features an upgraded stainless steel heat exchanger and high 94% efficiency. These new boilers are great value with the cost of a new boiler being relatively low.

Heat output: 26.1kW
Stainless Steel Heat Exchanger
OpenTherm compatible

(Boiler-only price: comparing multiple suppliers, including Screwfix and Plumbase where possible. Correct February 2024).

Key Features

The Alpha E-Tec NXS system boiler is Alpha’s primary system boiler offering for the residential market. It boasts a new thermoplastic-wrapped stainless steel heat exchanger and is up to 94% efficient.

Features

94% / A rated efficiency
Stainless steel heat exchanger making it highly efficient and durable
Ultra-compact dimensions – 712mm in height, 440mm wide and 255mm deep.
Premium components for a low price

Efficiency

94% / A rated efficiency
Stainless steel heat exchanger making it highly efficient and durable
Modulation rage of 1:6

Size and Installation

26.1kW gas system boiler
Available in 30.4kW and 34.8kW powers too
Ideal for installation in a cupboard
Quiet operation
Combined condensate and pressure valve

Control

User-friendly control
Customisable output on water and heating
On-boiler controls

Environmentally Friendly

Low CO2 emissions for reduced environmental impact
1:6 modulation enables running at reduced power output

More Information

More About The Alpha E-Tec 20 NXS System Boiler

Stainless steel heat exchanger

The latest version of Alpha’s stainless steel heat exchanger is moulded in thermoplastic to reduce weight whilst staying highly efficient. Stainless steel is both durable and lasts a long time.

A stainless steel heat exchanger is much better than aluminium it terms of longevity. Also, aluminium can lose up to 10% efficiency over 10 years. This directly affects your heating gas spend.

Inside a stainless steel Alpha heat exchanger.

Easy operation

The Alpha E-Tec 20 NXS is simple, easy to understand and control.

Alpha E-Tec NXS System Boiler Control Panel.

Weather compensation

Alpha Weather Compensation Probe – Fitted.

Weather compensation compatible with a simple external sensor connection. The Weather Compensation Probe is a smart device that optimises the performance of your boiler. This makes it more energy-efficient and cost-effective. By monitoring the temperature outside, the probe adjusts the heat output of your boiler. This ensures that it only produces the amount of heat that your home needs without wasting any energy.

If you have an E-Tec NXS system boiler, you can easily add the Weather Compensation Probe to it by installing the three-way diverter valve kit. This kit allows the probe to communicate with your boiler and regulate its heat output.

The Weather Compensation Probe is an excellent investment for anyone looking to save money on their energy bills.

OpenTherm compatible

‘OpenTherm’ is a communication protocol. It enables heating controls and boilers to exchange information. This allows the temperature flow through a heating system to be adjusted. This can lead to increased energy efficiency whilst maintaining the desired temperature in your home.

Boilerhut Review

Our Thoughts

Written by Bernard Morgan (Engineer). Published: February 28, 2024. Updated: December 18, 2025

The Alpha E-Tec 20 NXS system boiler is a great boiler with a stainless steel heat exchanger. This heat exchanger is one of the main reasons we install these over Worcester Bosch boilers. They’re also OpenTherm compatible meaning you can save money on heating bills. It also means your boiler will modulate down reducing stress on the internal components.

This boiler may not have some of the features that a Viessmann has but it is a very capable and reliable boiler. Alpha are known for their build quality and are only getting more popular in the UK.

Performance 8/10

The 20 NXS is 94% efficient. This means upgrading to this boiler will more than likely save you money on your heating bills. With OpenTherm and Weather Compensation it will ensure your home stays warm for the lowest cost.

Quality 7/10

Alpha uses a variety of materials, including brass, copper, composites, and plastics in their system boilers. Their heat exchanger is superior to many other boiler models.

Value 8/10

The Alpha E-Tec 20 NXS is a great value system boiler. Considering the heat exchanger, the price is very good especially compared to similar boilers from Worcester Bosch, for example. This boiler loses a point to the 7-year warranty. Viessmann and other manufacturers offer up to 12-year warranties.

Customer Satisfaction 9/10

Alpha Boilers, and in particular the E-Tec NXS model, have become very popular due to their reliable performance. While it’s true that no heating system is entirely free from malfunctions, it’s worth noting that only a few issues have been reported among the hundreds of Alpha boilers that have been installed.

Boilerhut is committed to delivering exceptional customer service, and we take pride in our ability to resolve any issues quickly and efficiently.

Specification

Manufacturer	Alpha
Model	E-Tec 20 NXS System Boiler
Condensing	Yes
Efficiency Rating	94%
Energy Efficiency Class	A Rated
Modulation Range	1:6
Warranty	7-year warranty
Central Heating Output – 80/60 °C	26.1kW
Mounting	Wall Mounted
Colour	White
Weight	30.6kg
Dimensions – Height	712mm
Dimensions – Width	440mm
Dimensions – Depth	255mm
Max Horizontal Flue Length	12m
Max Vertical Flue Length	14m

What’s Included

If you need a new or replacement boiler or are looking at having a central heating system installed, get an online quote (it takes less than 1 minute), and you’ll get an instant price. But what’s included and why choose Boilerhut:

Prices include everything to ensure the ongoing efficiency and longevity of your boiler
Flue, condensate pipe, fixtures and fittings
Main chemical flush
Wireless room thermostat
Magnetic and hard water filter
Labour and VAT included
Gas Safe manufacturer-trained installers for full warranty on completion
Building regulations
10-year manufacturer-backed warranty on the Vitodens 050-W 25kW.

Next day boiler installation. Quick central heating system installation.
‘Excellent’ 5* customer satisfaction on Trustpilot.
Finance options available for central heating or boiler installation.
Fixed prices. No hidden extras.
Get up to three quotes for different-tier boilers.
Instant, no-obligation quote in less than 1 minute.

Alpha E-Tec 20 NXS System Boiler

Features

Efficiency

Size and Installation

Control

Environmentally Friendly

More About The Alpha E-Tec 20 NXS System Boiler

Our Thoughts

Performance 8/10

Quality 7/10

Value 8/10

Customer Satisfaction 9/10

Support

Further reading and more information

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