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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

Are Heat Only Boilers Still Used?

09th February, 2026 Guides

Are Heat Only Boilers Still Us...

Despite technological advancements, heat-only boilers remain a prevalent choice for many h...

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Navien Boiler Error Codes

09th February, 2026 Guides

Navien Boiler Error Codes

Troubleshoot common Navien boiler error codes with iHeat, a leading UK provider of heating...

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Best Wall Mounted Air Conditioning

09th February, 2026 Guides

Best Wall Mounted Air Conditio...

Wall-mounted air conditioning refers to a type of air conditioner unit that is installed o...

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Best Bedroom Air Conditioning Units

09th February, 2026 Guides

Best Bedroom Air Conditioning...

When outfitting a bedroom with an air conditioner, it's crucial to understand the types av...

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Air Conditioning Costs

09th February, 2026 Guides

Air Conditioning Costs

In discussing air conditioning, it's important to understand the different systems availab...

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New Gas Boiler Technology & Features

06th February, 2026 Guides

New Gas Boiler Technology & Fe...

Modern gas boilers can offer significant advantages over older, less efficient models, fro...

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Viessmann Heat Pump - 2026 UK Guide

06th February, 2026 Reviews

Viessmann Heat Pump - 2026 UK...

Viessmann offers an impressive range of heat pumps in the UK for 2026, catering to various...

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Does a Worcester Bosch Boiler Need a Service?

06th February, 2026 Guides

Does a Worcester Bosch Boiler...

Regular maintenance of Worcester Bosch boilers is essential to ensure safety and efficienc...

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Oil Boiler Not Firing Up - Common Causes and fixes

06th February, 2026 Guides

Oil Boiler Not Firing Up - Com...

An oil boiler often refuses to start due to common issues like empty oil tanks, power supp...

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Boiler Warranty Invalid? Warranty Checklist

06th February, 2026 Guides

Boiler Warranty Invalid? Warra...

This article explains what a boiler warranty covers, what actions can invalidate it, and h...

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Boiler Parts and Their Functions

06th February, 2026 Guides

Boiler Parts and Their Functio...

Understanding the different parts of a boiler and their functions is essential for homeown...

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Electric Boiler Service

06th February, 2026 Guides

Electric Boiler Service

Electric boilers are popular in many UK homes due to their efficiency and compatibility wi...

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