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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

Why Is My Radiator Cold At The Bottom?

25th September, 2026 Advice

Why Is My Radiator Cold At The...

A radiator that stays cold at the bottom may have restricted water flow, often associated...

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Boiler Diverter Valve: Symptoms, Repair and Replacement

25th September, 2026 Advice

Boiler Diverter Valve: Symptom...

A boiler diverter valve directs heat to your heating or hot water.

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Radiators Not Heating Up: How to Fix?

25th September, 2026 Guides

Radiators Not Heating Up: How...

If one radiator isn't working while the others are hot, the problem is usually local to th...

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One Radiator Not Working In One Room

25th September, 2026 Guides

One Radiator Not Working In On...

A radiator not heating up properly can be frustrating. There are several reasons this migh...

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October Energy Price Cap Rise: What It Means for Solar and Battery Storage

25th September, 2026 News

October Energy Price Cap Rise:...

The energy price cap rises by 4% from 1 October 2026, with higher gas prices driving most...

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iHeat Support Gas Safety Week 2026

15th September, 2026 Guides

iHeat Support Gas Safety Week...

Gas Safety Week 2026 takes place from 14 to 20 September, helping raise awareness of how t...

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Vaillant F72 Error Code - How To Fix

15th September, 2026 Guides

Vaillant F72 Error Code - How...

F72 usually points to a sensor fault or poor circulation in the heating system.

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Buying a Boiler Online: Prices and Installation Costs

14th September, 2026 Guides

Buying a Boiler Online: Prices...

See real advertised boiler package prices, what your installation quote should cover and w...

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New Boiler Costs UK: Installation Prices Explained (2026)

14th September, 2026 Guides

New Boiler Costs UK: Installat...

iHeat's average boiler installation order value was around £2,800 including VAT for Septem...

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Vented vs Unvented Cylinders: Which Is Right for Your Home?

14th September, 2026 Comparisons

Vented vs Unvented Cylinders:...

Compare water pressure, space, direct and indirect heating, installation requirements and...

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Boiler Condensate Pipe: What It Is, Where It Goes and Problems

14th September, 2026 Advice

Boiler Condensate Pipe: What I...

Identify your boiler condensate pipe, understand indoor and outdoor drainage, and learn wh...

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Ideal vs Worcester Bosch: Which Boiler Should You Choose?

14th September, 2026 Comparisons

Ideal vs Worcester Bosch: Whic...

Compare equivalent Ideal and Worcester Bosch boilers using published flow rates, dimension...

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