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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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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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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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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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Oil Fired Boiler

06th February, 2026 Guides

Oil Fired Boiler

An oil fired boiler is a heating system that uses oil as its fuel to heat water for centra...

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What is an Immersion Heater and What Does it Cost?

06th February, 2026 Advice

What is an Immersion Heater an...

Everything UK homeowners need to know about immersion heaters and running costs.

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How Old is My Boiler and When to Consider a Replacement?

06th February, 2026 Guides

How Old is My Boiler and When...

A modern, efficient boiler can operate at over 90% efficiency, leading to significant savi...

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Why Putting a Boiler Outside Is Often a Bad Idea

06th February, 2026 Guides

Why Putting a Boiler Outside I...

While putting a boiler outside may seem like a good idea to save space and reduce noise in...

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What is Boiler Frost Protection?

06th February, 2026 Guides

What is Boiler Frost Protectio...

Boiler frost protection is an important feature that helps prevent your boiler from freezi...

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How to increase boiler efficiency

06th February, 2026 Guides

How to increase boiler efficie...

Want to maximise your boiler efficiency in cold weather? Our guide provides tips on how to...

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Disadvantages of Oil Boilers: Exploring Key Concerns

06th February, 2026 Guides

Disadvantages of Oil Boilers:...

Oil boilers may be a popular choice for home heating, but they come with some significant...

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