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Stephen Day

Gas Safe Engineer at iHeat

Stephen Day is a Gas Safe registered and FGAS certified engineer with over 20 years of hands-on experience in the heating, cooling, and renewable energy industry, specialising in boiler installations, air conditioning, and heat pump systems.

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About Stephen Day

Stephen Day is a Gas Safe registered and FGAS certified engineer with over 20 years of hands-on experience in the heating, cooling and renewable energy industry.

Throughout his career, Stephen has designed, installed and maintained thousands of systems across homes and businesses in the UK. His background on the tools, combined with his directorship role at iHeat, gives him a rare understanding of both the technical and operational sides of the industry.

He has helped to secure Which? Trusted Trader accreditation all with a focus on delivering great service and long-term value for customers. He also writes for the iHeat blog, sharing practical advice and explaining heating topics in plain, helpful language.

Stephen continues to stay up to date with the latest heating technologies, building regulations and low-carbon innovations.

Gas Safe ID: 5910722

Expertise

  • Boiler systems and installation
  • Heat pumps and hybrid heating systems
  • Gas safety and compliance
  • System design
  • Renewable and low-carbon technologies
  • Technical training


Articles by Stephen Day are reviewed by iHeat’s technical team for accuracy and reliability.

Stephen Day's latest articles

The Best Budget Boiler in 2026

19th December, 2025 Guides

The Best Budget Boiler in 2026

The best budget boilers are Ideal, Alpha, Baxi, Worcester Bosch and Vaillant models, compa...

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Most Reliable Boiler Brands In 2026: Trusted UK Picks

19th December, 2025 Guides

Most Reliable Boiler Brands In...

The most reliable boiler brands in the UK: Worcester Bosch, Vaillant, Ideal, Viessmann, an...

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What is an Airing Cupboard?

19th December, 2025 Guides

What is an Airing Cupboard?

An airing cupboard is a heated storage space that uses warmth from a hot water cylinder or...

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Boiler Pressure Too High: What It Means and How to Fix It

19th December, 2025 Advice

Boiler Pressure Too High: What...

High boiler pressure is usually anything above 2.5 bar on the pressure gauge when the heat...

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Worcester Bosch vs Vaillant Boilers - Which is Better?

19th December, 2025 Advice

Worcester Bosch vs Vaillant Bo...

A clear comparison of Worcester Bosch and Vaillant Boilers and why Worcester Bosch is ofte...

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Best Boiler for Terraced House

18th December, 2025 Guides

Best Boiler for Terraced House

Searching for the best boiler brand for terraced housing? Our guide compares the top-rated...

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Which Boiler is Best for a 4 Bedroom Home?

18th December, 2025 Guides

Which Boiler is Best for a 4 B...

When your old boiler breaks down and it comes time to replace it with a new one, it might...

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Best Shower for Combi Boiler

18th December, 2025 Guides

Best Shower for Combi Boiler

A combination boiler, commonly known as a combi boiler, is an advanced heating unit that p...

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Which Boiler is Best for a 3 Bedroom Home?

18th December, 2025 Guides

Which Boiler is Best for a 3 B...

Picking the correct size combi boiler for your home

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Best Heating for Off-Grid Homes

18th December, 2025 Guides

Best Heating for Off-Grid Home...

Homes that are not connected to the mains gas grid in the UK need alternative heating syst...

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The Best LPG Combi Boilers 2025

18th December, 2025 Guides

The Best LPG Combi Boilers 202...

You may have heard of LPG boilers before, but even if you are not familiar with them, they...

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Best Electric Combi Boilers (Electric-Only Guide)

16th December, 2025 Guides

Best Electric Combi Boilers (E...

The best electric combi boilers in 2025 include models from Electric Heating Company, Heat...

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