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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 Not Working, No Fault Code

05th February, 2026 Guides

Vaillant Boiler Not Working, N...

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

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What is Central Heating Sludge?

05th February, 2026 Guides

What is Central Heating Sludge...

Sludge in a central heating system is a mix of dirt, rust, and limescale. Over time, these...

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Power Flush vs Chemical Flush

05th February, 2026 Comparisons

Power Flush vs Chemical Flush

Both a power flush and chemical flush are forms of system cleaning you can use for your ce...

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Boiler Service Liverpool

05th February, 2026 Guides

Boiler Service Liverpool

The price of a boiler service is influenced by various factors including the type of boile...

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Worcester Bosch Greenstar Ri Heat-Only Boiler Review

05th February, 2026 Guides

Worcester Bosch Greenstar Ri H...

Heat-only boilers, also known as 'regular' or 'conventional' boilers, form a vital compone...

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Underfloor Heating with a Combi Boiler

05th 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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Boiler Won't Turn Off

05th February, 2026 Guides

Boiler Won't Turn Off

When a boiler fails to turn off, it can lead to excessive energy usage and potentially har...

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What Is A Powerflush?

05th February, 2026 Advice

What Is A Powerflush?

A powerflush is a kind of cleaning process for your central heating system that can remove...

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How to Reset Glow Worm Boiler

05th February, 2026 Guides

How to Reset Glow Worm Boiler

Taking care of your Glow-worm boiler means not only understanding how to reset it but also...

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How To Free A Stuck Diverter Valve In Your Boiler - An Expert Guide

05th February, 2026 Guides

How To Free A Stuck Diverter V...

A diverter valve is an essential component of a combi boiler. Its main job is to control t...

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Do I Need a Carbon Monoxide Detector with a Combi Boiler

05th February, 2026 Guides

Do I Need a Carbon Monoxide De...

Boilers can produce carbon monoxide (CO), a dangerous and potentially deadly gas, through...

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Boiler Pump Not Working

05th February, 2026 Guides

Boiler Pump Not Working

A boiler pump is a vital part of a heating system. It ensures water is circulated efficien...

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