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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 Old Boilers Expensive to Run?

06th February, 2026 Guides

Are Old Boilers Expensive to R...

Old boilers can be expensive to run, as they are often less efficient and more prone to br...

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What is the Cheapest Way to Heat a House?

06th February, 2026 Guides

What is the Cheapest Way to He...

Heating your home should not be a decision ruled by fear of overspending on your bills, es...

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F75 Vaillant Error Code

06th February, 2026 Guides

F75 Vaillant Error Code

One of the most common and frustrating error codes your Vaillant boiler can present to you...

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Moving Boiler To The Attic Or Garage

06th February, 2026 Advice

Moving Boiler To The Attic Or...

If you believe you would benefit from moving your boiler to a new location, either for fin...

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How much cheaper is a new boiler to run?

06th February, 2026 Guides

How much cheaper is a new boil...

New boilers are in fact much cheaper to run than old boilers, this is down to a number of...

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Heat Pumps: The Ultimate UK guide

06th February, 2026 Guides

Heat Pumps: The Ultimate UK gu...

As energy efficiency and environmental concerns continue to shape our choices, heat pumps...

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Boiler Circulation Pump Replacement Costs

06th February, 2026 Guides

Boiler Circulation Pump Replac...

Here at iHeat we’re boiler experts, this includes an extensive bank of component knowledge...

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Alpha E-Tec Hybrid Heat Pump

06th February, 2026 Advice

Alpha E-Tec Hybrid Heat Pump

You may have heard of a heat pump, you probably have heard of a boiler, you probably have...

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Potterton Boiler (Combi Range)

06th February, 2026 Guides

Potterton Boiler (Combi Range)

Potterton are a brand with a celebrated lineage of expertise when it comes to heating, Pot...

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Combi Boilers vs Conventional Boilers

06th February, 2026 Guides

Combi Boilers vs Conventional...

Combi boilers, also known as combination boilers, are compact units that serve as both a c...

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Wall-mounted or floor-standing boiler?

06th February, 2026 Comparisons

Wall-mounted or floor-standing...

Choosing between a wall-mounted and a floor-standing boiler mostly depends on the type of...

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Ideal Boilers - Vogue Range

06th February, 2026 Guides

Ideal Boilers - Vogue Range

The Ideal Boilers' Vogue Range stands out as a premium selection, consistent with the comp...

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