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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

Navien Combi Boiler Costs

10th September, 2026 Guides

Navien Combi Boiler Costs

Navien combi boilers have secured a competitive edge by providing both central heating and...

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Checking Your Boiler When Buying a New Home

10th September, 2026 Advice

Checking Your Boiler When Buyi...

Buying a new home is a massive investment and you’ll likely consider a number of different...

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When Should You Replace Your Boiler?

10th September, 2026 Guides

When Should You Replace Your B...

It can cost a lot to get the right boiler installed into your home, which is why a lot of...

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Are You About to Spend Too Much on a New Boiler?

10th September, 2026 Guides

Are You About to Spend Too Muc...

According to a 2017 study by uSwitch, 18% of UK households had experienced a boiler breakd...

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Why Is Boiler Water Treatment Important?

10th September, 2026 Guides

Why Is Boiler Water Treatment...

In boiler systems, water treatment involves several techniques. These methods remove impur...

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Oil Fired Boiler

10th September, 2026 Guides

Oil Fired Boiler

Oil-fired boilers use stored heating oil to provide heating and hot water, particularly in...

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Most Energy Efficient Boilers in 2026 (UK Guide)

10th September, 2026 Guides

Most Energy Efficient Boilers...

The efficiency of your boiler may not be something you pay much attention to, but is it co...

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Best Shower for Combi Boiler

07th September, 2026 Guides

Best Shower for Combi Boiler

A thermostatic mixer shower is generally the best shower for a combi boiler, combining the...

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Boiler Leaking Water? (How to Fix a Leaking Boiler)

07th September, 2026 Advice

Boiler Leaking Water? (How to...

If your boiler is leaking water, it’s likely due to pressure or worn parts. Acting fast he...

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Are Boiler Hot Water Storage Tanks a Necessity?

07th September, 2026 Guides

Are Boiler Hot Water Storage T...

You may be wondering, are hot water storage tanks essential to home heating and the runnin...

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Why Is My Boiler Still Running When All My Smart TRVs Are Closed?

07th September, 2026 Guides

Why Is My Boiler Still Running...

If all your smart TRVs are closed but your boiler is still running, another heating contro...

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Hot Water Tank Thermostat

04th September, 2026 Guides

Hot Water Tank Thermostat

A hot water cylinder thermostat should generally be set to around 60°C.

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