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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 Ecotec Pro Review

04th February, 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 Boilers Reviews

04th February, 2026 Reviews

Vaillant Boilers Reviews

Vaillant offers an extensive selection of boilers to cater to different household requirem...

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Vaillant Boiler Red Light

04th February, 2026 Guides

Vaillant Boiler Red Light

Understanding what the red light and associated fault codes mean is vital for boiler owner...

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Vaillant Boiler Parts 2026

04th February, 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 No Hot Water

04th February, 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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Vaillant Boiler Error Codes

04th February, 2026 Guides

Vaillant Boiler Error Codes

Read all about the most common Vaillant boiler error codes, what they mean and how you can...

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Unusual Boiler Smells: Causes and Fixes

04th February, 2026 Guides

Unusual Boiler Smells: Causes...

Unusual boiler smells can be a sign of a serious problem, such as a gas leak or bacterial...

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Underfloor Heating with a Combi Boiler

04th February, 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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Solar Panel Costs and Boiler Compatibility

04th February, 2026 Guides

Solar Panel Costs and Boiler C...

As the world continues to grapple with environmental challenges, the adoption of renewable...

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Shower Going Hot and Cold - Combi Boiler

04th February, 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

04th February, 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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Ravenheat Boiler Error Codes

04th February, 2026 Guides

Ravenheat Boiler Error Codes

Error codes can range from ignition troubles to pressure fluctuations, each denoting a spe...

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