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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

Air conditioning replacement: when to repair and when to replace

27th March, 2026 Advice

Air conditioning replacement:...

If your air conditioning is unreliable or costly to run, replacement may make more sense.

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How Much Does a Heat Pump Cost? 2026 Guide

27th March, 2026 Guides

How Much Does a Heat Pump Cost...

In the UK, a heat pump usually costs several thousand pounds, with most air source systems...

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Ideal F2 Error Code - How to Fix

27th March, 2026 Guides

Ideal F2 Error Code - How to F...

Ideal F2 usually means flame loss.

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Worcester Boiler Fault 227

27th March, 2026 Guides

Worcester Boiler Fault 227

Boiler systems utilise error codes as an internal diagnostic tool. They offer a swift indi...

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Best Wall Mounted Air Conditioning

26th March, 2026 Guides

Best Wall Mounted Air Conditio...

The best wall mounted air conditioning unit depends on your room, budget and year-round ne...

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Worcester Bosch Boiler Pressure - UK Mega Guide

26th March, 2026 Guides

Worcester Bosch Boiler Pressur...

Worcester boiler pressure should usually sit around 1 to 1.5 bar when the system is cold

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Megaflow System - What is a Megaflow System and How Much do they Cost?

25th March, 2026 Guides

Megaflow System - What is a Me...

A Megaflow system is often worth considering if your home needs stronger hot water pressur...

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What temperature should I set my air conditioning to?

20th March, 2026 Advice

What temperature should I set...

For most UK homes, 24 to 26°C is a good starting point for cooling.

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How to Fix Boiler Airlock: Expert Guide

20th March, 2026 Guides

How to Fix Boiler Airlock: Exp...

A boiler airlock is usually a heating system circulation issue caused by trapped air, rath...

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Vaillant Boiler F22

19th March, 2026 Guides

Vaillant Boiler F22

The Vaillant F22 fault means your boiler pressure is too low and needs topping up.

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How to Power Your Boiler with Solar Panels

19th March, 2026 Advice

How to Power Your Boiler with...

Solar panels can lower energy use, but most combi boilers are not directly powered by sola...

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F83 Vaillant Error Code

19th March, 2026 Guides

F83 Vaillant Error Code

A Vaillant F83 fault usually means the boiler is not detecting the temperature rise it exp...

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