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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

Boiler Losing Pressure, What Should You Do (How To Fix)

11th December, 2025 Advice

Boiler Losing Pressure, What S...

A boiler losing pressure is usually caused by a leak, trapped air, or a faulty valve - her...

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How To Fix Sludge in Radiators

11th December, 2025 Advice

How To Fix Sludge in Radiators

If you’ve noticed your energy bills rising recently, this could be down to a number of rea...

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Radiators Not Heating Up: How to Fix?

11th December, 2025 Guides

Radiators Not Heating Up: How...

If your radiators aren’t heating up, it’s usually caused by trapped air, sludge, or a boil...

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What Temperature Should My Boiler Be Set At In Winter?

09th December, 2025 Guides

What Temperature Should My Boi...

Most homes stay warm in winter with heating set at 60 to 70°C and hot water at 50 to 55°C.

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Central Heating System

09th December, 2025 Guides

Central Heating System

A simple breakdown of the main central heating systems in UK homes and how to decide which...

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Do Radiator Covers Block Heat?

08th December, 2025 Guides

Do Radiator Covers Block Heat?

Radiator covers can reduce heat output if airflow is restricted, but the effect varies by...

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Leaking Overflow Pipe - Causes and Fixes

05th December, 2025 Advice

Leaking Overflow Pipe - Causes...

A leaking overflow pipe is usually caused by high boiler pressure or a faulty valve.

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Do You Need New Radiators for Heat Pumps?

05th December, 2025 Advice

Do You Need New Radiators for...

Most homes need some radiators upgraded for a heat pump, but usually not all of them.

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Hive App Not Working? Here's Why And How to Fix

28th November, 2025 Guides

Hive App Not Working? Here's W...

Most Hive heating issues come from lost connection, low batteries, receiver faults or boil...

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Leaking Radiator Valve (Lockshield)

28th November, 2025 Guides

Leaking Radiator Valve (Locksh...

A leaking lockshield valve is usually caused by a loose gland nut, worn seal or corrosion,...

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High Temperature Heat Pumps UK - Are They Worth It?

28th November, 2025 Advice

High Temperature Heat Pumps UK...

High temperature heat pumps work like boilers without needing radiators, but they cost mor...

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Why is My Boiler Not Working?

27th November, 2025 Guides

Why is My Boiler Not Working?

Maintaining a boiler in good working order is essential for its efficiency and longevity....

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