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

The Pros & Cons of Air Source Heat Pumps in 2026

05th January, 2026 Guides

The Pros & Cons of Air Source...

Air Source Heat Pumps have become a popular choice for renewable heating in the UK. They e...

read article arrow Read Article
Air Source Heat Pump Grant 2026

05th January, 2026 Guides

Air Source Heat Pump Grant 202...

An air source heat pump (ASHP) is a device that transfers heat from the outside air to pro...

read article arrow Read Article
Boiler Plus - 2026 Guide

05th January, 2026 Guides

Boiler Plus - 2026 Guide

Boiler Plus is a set of energy efficiency standards introduced by the UK government. It ai...

read article arrow Read Article
The Best Air Source Heat Pumps 2026

05th January, 2026 Advice

The Best Air Source Heat Pumps...

This guide outlines the best air source heat pumps for UK homes in 2026 and what to know b...

read article arrow Read Article
Which Boiler is Best for a 4 Bedroom Home?

22nd December, 2025 Guides

Which Boiler is Best for a 4 B...

When your old boiler breaks down and it comes time to replace it with a new one, it might...

read article arrow Read Article
This Valentine's Day we’re asking - Does the size of your pipe really matter? 2025

22nd December, 2025 Guides

This Valentine's Day we’re ask...

This Valentine’s Day we want to let you in on a dirty little secret…

read article arrow Read Article
The Best Budget Boiler in 2026

19th December, 2025 Guides

The Best Budget Boiler in 2026

The best budget boilers are Ideal, Alpha, Baxi, Worcester Bosch and Vaillant models, compa...

read article arrow Read Article
Most Reliable Boiler Brands In 2026: Trusted UK Picks

19th December, 2025 Guides

Most Reliable Boiler Brands In...

The most reliable boiler brands in the UK: Worcester Bosch, Vaillant, Ideal, Viessmann, an...

read article arrow Read Article
What is an Airing Cupboard?

19th December, 2025 Guides

What is an Airing Cupboard?

An airing cupboard is a heated storage space that uses warmth from a hot water cylinder or...

read article arrow Read Article
Boiler Pressure Too High: What It Means and How to Fix It

19th December, 2025 Advice

Boiler Pressure Too High: What...

High boiler pressure is usually anything above 2.5 bar on the pressure gauge when the heat...

read article arrow Read Article
Worcester Bosch vs Vaillant Boilers - Which is Better?

19th December, 2025 Advice

Worcester Bosch vs Vaillant Bo...

A clear comparison of Worcester Bosch and Vaillant Boilers and why Worcester Bosch is ofte...

read article arrow Read Article
Best Boiler for Terraced House

18th December, 2025 Guides

Best Boiler for Terraced House

Searching for the best boiler brand for terraced housing? Our guide compares the top-rated...

read article arrow Read Article