Stephen Day profile photo

Stephen Day

Gas Safe Engineer

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.

LinkedIn

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.

Expertise & Focus Areas

  • 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

Radiators Not Heating Up: How to Fix?

17th October, 2025 Guides

Radiators Not Heating Up: How...

If your radiators aren’t heating up, it could be caused by a few things, such as trapped a...

read article arrow Read Article
F22 Vaillant Fault Code

17th October, 2025 Guides

F22 Vaillant Fault Code

Boiler error codes are crucial indicators for identifying and diagnosing issues within hea...

read article arrow Read Article
How much does a new boiler cost in the UK

17th October, 2025 Guides

How much does a new boiler cos...

New boiler cost can be a baffling topic, but our iHeat expert guide will clear things up!

read article arrow Read Article
Boiler Pressure Too High? Causes And How To Fix It

16th October, 2025 Advice

Boiler Pressure Too High? Caus...

What happens when your boiler pressure goes too high, some possible causes and how to fix...

read article arrow Read Article
What is an Immersion Heater and What Does it Cost?

16th October, 2025 Advice

What is an Immersion Heater an...

The definitive guide on immersion heaters

read article arrow Read Article
Vaillant F28 Error Code - How to Fix?

16th October, 2025 Guides

Vaillant F28 Error Code - How...

Any time your boiler displays an error code, it can be a huge stressor, especially if it d...

read article arrow Read Article
What is an Airing Cupboard?

16th October, 2025 Guides

What is an Airing Cupboard?

An airing cupboard is a small space used to store and dry laundry, usually located near th...

read article arrow Read Article
Boiler Not Working? Most Common Problems (And Fixes)

16th October, 2025 Advice

Boiler Not Working? Most Commo...

A complete guide to getting that boiler working again and some common fault codes and how...

read article arrow Read Article
Back Boiler Replacement Costs, Guide and Tips

16th October, 2025 Guides

Back Boiler Replacement Costs,...

Should you replace that beaten up old back boiler and get with the times?

read article arrow Read Article
Boilers on Finance - The Best Pay Monthly and 0% Interest Deal

16th October, 2025 Guides

Boilers on Finance - The Best...

Buying a boiler on finance can be hard with all the different options available. Let us ex...

read article arrow Read Article
Understanding Boiler kW (Kilowatts) & How To Measure

16th October, 2025 Guides

Understanding Boiler kW (Kilow...

When it comes to choosing a boiler for your home, understanding the concept of kilowatts (...

read article arrow Read Article
Best Compact (Small) Combi Boiler in 2025

16th October, 2025 Guides

Best Compact (Small) Combi Boi...

When shopping for a boiler, many people forget to check the physical dimensions of each mo...

read article arrow Read Article