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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

Can You Leave Air Conditioning On Overnight?

28th May, 2026 Advice

Can You Leave Air Conditioning...

Yes, in most homes it is completely safe to leave air conditioning on overnight, particula...

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How do I know if my air conditioning system needs regassing?

28th May, 2026 Guides

How do I know if my air condit...

If your air conditioning system is no longer cooling rooms properly, takes much longer to...

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Why Your AC is Freezing Up & What to Do

28th May, 2026 Advice

Why Your AC is Freezing Up & W...

If your air conditioner is freezing up, it is usually caused by restricted airflow, dirty...

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Why Is My Air Conditioner Making Noise?

27th May, 2026 Guides

Why Is My Air Conditioner Maki...

Air conditioners naturally make some noise while running, but unusual sounds such as rattl...

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How Air Conditioning Can Help Reduce Hay Fever and Allergies

22nd May, 2026 Advice

How Air Conditioning Can Help...

Air conditioning can help reduce some hay fever and allergy symptoms by improving airflow...

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Why Does the Air Conditioner Smell Bad?

22nd May, 2026 Advice

Why Does the Air Conditioner S...

Air conditioning smells are usually caused by moisture, dust, or dirty filters building up...

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Can Air Conditioning Improve Indoor Air Quality?

22nd May, 2026 Guides

Can Air Conditioning Improve I...

Air conditioning can help improve indoor air quality by improving airflow, reducing humidi...

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How Often Should Air Conditioner Filters Be Cleaned?

22nd May, 2026 Advice

How Often Should Air Condition...

Air conditioner filters should usually be cleaned every two to four weeks during periods o...

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Why is My Air Conditioner Blowing Warm Air Instead of Cool?

22nd May, 2026 Advice

Why is My Air Conditioner Blow...

If an air conditioner is blowing warm air instead of cool air, it is often caused by dirty...

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Types Of Air Conditioning - Options For UK Homes

22nd May, 2026 Advice

Types Of Air Conditioning - Op...

This guide helps you choose the best type of air conditioning for your UK home.

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What Size Air Conditioner Do I Need in the UK?

22nd May, 2026 Advice

What Size Air Conditioner Do I...

Room size matters, but heat, glazing, and usage matter too.

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Portable Vs Wall-Mounted Air Conditioning: Which Is Better?

22nd May, 2026 Comparisons

Portable Vs Wall-Mounted Air C...

Portable and wall mounted air conditioning both have their own strengths and drawbacks dep...

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