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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

Best Boiler Brands in the UK (2026) Top Manufacturers

30th September, 2026 Guides

Best Boiler Brands in the UK (...

Compare the UK's top boiler manufacturers for 2026.

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Boiler Diverter Valve: Symptoms, Repair and Replacement

30th September, 2026 Advice

Boiler Diverter Valve: Symptom...

A boiler diverter valve directs heat to your heating or hot water.

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What Is A System Boiler?

30th September, 2026 Advice

What Is A System Boiler?

A system boiler provides heating and stores hot water in a separate cylinder.

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Combi Boiler Replacement Cost

30th September, 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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How long does it take to fit a new boiler?

30th September, 2026 Guides

How long does it take to fit a...

Most boiler installations take between one and two days depending on your current setup an...

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Can A New Boiler Increase the Value of My House?

30th September, 2026 Advice

Can A New Boiler Increase the...

Have you considered a new boiler to increase the value of your home? We run through why th...

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Most Energy Efficient Boilers in 2026 (UK Guide)

30th September, 2026 Guides

Most Energy Efficient Boilers...

The efficiency of your boiler may not be something you pay much attention to, but is it co...

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What Size Combi Boiler Do I Need?

30th September, 2026 Advice

What Size Combi Boiler Do I Ne...

Find out whether the size of your combi boiler will make any difference to its capabilitie...

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Back Boiler Replacement Cost in the UK

30th September, 2026 Guides

Back Boiler Replacement Cost i...

Back boilers are outdated, inefficient, and pose safety risks. Upgrading to a combi boiler...

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Boiler Leaking Water? (How to Fix a Leaking Boiler)

30th September, 2026 Advice

Boiler Leaking Water? (How to...

If your boiler is leaking water, it’s likely due to pressure or worn parts. Acting fast he...

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New Boiler Costs UK: Installation Prices Explained

30th September, 2026 Guides

New Boiler Costs UK: Installat...

iHeat's average boiler installation order value was around £2,800 including VAT for Septem...

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Worcester Bosch boiler flashing blue light with no error code: what to check

30th September, 2026 Guides

Worcester Bosch boiler flashin...

A flashing blue light can indicate a fault on some Worcester boilers, but its exact meanin...

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