Stephen Day profile photo

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.

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.

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...

read article arrow Read Article
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...

read article arrow Read Article
Air Source Heating - Air to Air Source Heat Pump

21st May, 2026 Guides

Air Source Heating - Air to Ai...

Air source heating harnesses environmental warmth to heat homes efficiently, utilizing a d...

read article arrow Read Article
Boiler Installation Cost Calculator

21st May, 2026 Guides

Boiler Installation Cost Calcu...

Unlock the insights you need to estimate boiler costs in the UK accurately. Our comprehens...

read article arrow Read Article
Vented vs Unvented Hot Water Cylinders

21st May, 2026 Comparisons

Vented vs Unvented Hot Water C...

Homes will need a new boiler every 10 to 15 years to ensure they are safe and running effi...

read article arrow Read Article
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...

read article arrow Read Article
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...

read article arrow Read Article
Boiler Service London

21st May, 2026 Guides

Boiler Service London

A typical Annual Boiler Service includes a visual inspection to identify any obvious fault...

read article arrow Read Article
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...

read article arrow Read Article
Baxi Combi Boiler Costs

21st May, 2026 Guides

Baxi Combi Boiler Costs

A newer, high-end Baxi combi boiler not only aims to save on space but can also offer sign...

read article arrow Read Article
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...

read article arrow Read Article
Boiler Heat Exchanger Replacement Cost

21st May, 2026 Guides

Boiler Heat Exchanger Replacem...

A boiler heat exchanger is a crucial component in heating systems. It allows heat transfer...

read article arrow Read Article