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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

Electric Boiler vs Gas Boiler

21st May, 2026 Comparisons

Electric Boiler vs Gas Boiler

In this article we will discuss the topic of different boiler types, specifically electric...

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Best Heating for Off-Grid Homes

21st May, 2026 Guides

Best Heating for Off-Grid Home...

Homes that are not connected to the mains gas grid in the UK need alternative heating syst...

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How to Fix a Faulty Heat Exchanger

21st May, 2026 Advice

How to Fix a Faulty Heat Excha...

In this guide, we’re going to be explaining what a heat exchanger is, some common causes f...

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Worcester Bosch Greenstar 4000 Combi

21st May, 2026 Reviews

Worcester Bosch Greenstar 4000...

An in-depth review of the Worcester Bosch Greenstar 4000 Combi boiler, taking a look at it...

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Why is My Boiler Making a Humming Noise?

21st May, 2026 Guides

Why is My Boiler Making a Humm...

Boiler noises are frequent issues that signal varied problems within the system. From slig...

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Which Boiler is Best for an Apartment or Flat?

21st May, 2026 Advice

Which Boiler is Best for an Ap...

When your old boiler breaks down and it comes time to replace it with a new one, it may se...

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Boiler Pilot Light Won't Stay Lit

21st May, 2026 Advice

Boiler Pilot Light Won't Stay...

If you own an older boiler, you might be familiar with the pilot light. The pilot light is...

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Boiler Warranties & Guarantees: Top UK Brands for Best Value

21st May, 2026 Guides

Boiler Warranties & Guarantees...

Boiler warranties and guarantees are essential aspects to consider when investing in a new...

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Combi Boiler Valve Positions Explained

21st May, 2026 Guides

Combi Boiler Valve Positions E...

With the advancements in boiler technology by 2026, understanding the various valve positi...

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Boiler Not Responding To Thermostat

21st May, 2026 Advice

Boiler Not Responding To Therm...

When your boiler isn’t responding to its thermostat, or vice versa, it can be tricky to id...

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Grundfos Central Heating Pump

21st May, 2026 Guides

Grundfos Central Heating Pump

A Grundfos central heating pump is an essential part of a boiler system in many UK homes....

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How To Drain Central Heating System

21st May, 2026 Guides

How To Drain Central Heating S...

Understanding how to properly drain the system is vital for homeowners and DIY enthusiasts...

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