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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 Boiler Parts 2026

20th May, 2026 Guides

Vaillant Boiler Parts 2026

Vaillant boilers use a variety of parts to ensure efficient operation. This section looks...

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Vaillant Boiler Not Working, No Fault Code

20th May, 2026 Guides

Vaillant Boiler Not Working, N...

Boiler error codes provide essential diagnostics for homeowners and engineers alike, signa...

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Vaillant Boiler No Hot Water

20th May, 2026 Guides

Vaillant Boiler No Hot Water

Understanding why a Vaillant boiler fails to provide hot water entails recognising the sig...

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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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Shower Going Hot and Cold - Combi Boiler

20th May, 2026 Guides

Shower Going Hot and Cold - Co...

Within homes across the UK, the combination boiler, commonly known as a combi boiler, serv...

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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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Combi Boiler Replacement Cost

20th May, 2026 Guides

Combi Boiler Replacement Cost

Replacing your boiler can be a stressful and costly process. That’s why we have written th...

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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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Ravenheat Boiler - Combi Prices 2026

20th May, 2026 Guides

Ravenheat Boiler - Combi Price...

Ravenheat combi boilers are known for their affordability and efficiency. They include mod...

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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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