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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

Vokera Boiler Red Light

05th February, 2026 Guides

Vokera Boiler Red Light

When a Vokera boiler presents a red light, it often indicates a lockout due to safety mech...

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Vokera Boiler Error Codes - How To Fix

05th February, 2026 Guides

Vokera Boiler Error Codes - Ho...

Familiarising yourself with common Vokera fault codes and their meanings can be crucial in...

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Viessmann F4 Fault

05th February, 2026 Guides

Viessmann F4 Fault

Boiler error codes are critical indicators that help identify specific issues within a boi...

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Viessmann F2 Fault

05th February, 2026 Guides

Viessmann F2 Fault

Error codes are integral to the effective operation and maintenance of modern boilers. The...

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Viessmann 222-F Boiler Review

05th February, 2026 Reviews

Viessmann 222-F Boiler Review

Viessmann is an international brand with over a century of trusted design and application,...

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Vaillant PCB

05th February, 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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F83 Vaillant Error Code

05th February, 2026 Guides

F83 Vaillant Error Code

Boiler error codes are essential indicators assisting in the diagnostics of potential issu...

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Vaillant F62 Fault Code

05th February, 2026 Guides

Vaillant F62 Fault Code

Error codes on boilers can be a confusing and frustrating topic, here at iHeat we want to...

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Vaillant F49 Boiler Error Code - How To Fix

05th February, 2026 Guides

Vaillant F49 Boiler Error Code...

The Vaillant F49 error code is a specific fault indicator on Vaillant boilers, signifying...

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Vaillant F23 Fault Code

05th February, 2026 Guides

Vaillant F23 Fault Code

When a boiler encounters a fault or malfunction, it communicates the problem through speci...

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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 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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