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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

Vaillant PCB

20th May, 2026 Guides

Vaillant PCB

A Vaillant boiler Printed Circuit Board (PCB) is a vital part of a modern boiler system. I...

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Vaillant Boiler Flue Extension

20th May, 2026 Guides

Vaillant Boiler Flue Extension

This guide dives deep into what flue extensions are, why they are important, and how to in...

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Vaillant Ecotec Pro Review

20th May, 2026 Reviews

Vaillant Ecotec Pro Review

Vaillant's Ecotec Pro combi boiler series is renowned for providing efficient heating and...

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Vaillant EcoTEC Plus

20th May, 2026 Reviews

Vaillant EcoTEC Plus

Vaillant UK manufactures some of the finest boilers on the market, highly efficient and ec...

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Vaillant Combi Boilers

20th May, 2026 Guides

Vaillant Combi Boilers

At iHeat We’ve joined forces with Vaillant UK to become the first online company to instal...

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Understanding Boiler kW (Kilowatts) & How To Measure

20th May, 2026 Guides

Understanding Boiler kW (Kilow...

When it comes to choosing a boiler for your home, understanding the concept of kilowatts (...

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Underfloor Heating with a Combi Boiler

20th May, 2026 Guides

Underfloor Heating with a Comb...

Integrating underfloor heating with existing combi boilers can be a practical option for m...

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S Plan Heating System

20th May, 2026 Guides

S Plan Heating System

An S-Plan heating system is a type of central heating system that provides efficient contr...

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Old Boiler - Replace Before Selling My House?

20th May, 2026 Guides

Old Boiler - Replace Before Se...

A well-maintained, efficient boiler is not only more attractive but can also suggest that...

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Reducing heat loss from your home

20th May, 2026 Guides

Reducing heat loss from your h...

Heat loss in a home happens when warm air escapes to the outside, and cold air infiltrates...

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Why Is My Radiator Not Working?

20th May, 2026 Advice

Why Is My Radiator Not Working...

When you have a radiator not working, there is not always an immediately obvious way to fi...

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Different Types Of Radiator Bleed Valves/Knobs Explained

20th May, 2026 Guides

Different Types Of Radiator Bl...

Radiator dials, often referred to as bleed valves or knobs, are crucial for managing the p...

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