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

Fitting A New Boiler to an Old System - Mega Guide

26th February, 2026 Guides

Fitting A New Boiler to an Old...

Replacing an old boiler with a new one involves several key steps that ensure safe and eff...

read article arrow Read Article
Ideal Temperature at Home

09th February, 2026 Advice

Ideal Temperature at Home

Finding and maintaining the right temperature in your home can feel like a constant battle...

read article arrow Read Article
Are Heat Only Boilers Still Used?

09th February, 2026 Guides

Are Heat Only Boilers Still Us...

Despite technological advancements, heat-only boilers remain a prevalent choice for many h...

read article arrow Read Article
Boiler Parts and Their Functions

06th February, 2026 Guides

Boiler Parts and Their Functio...

Understanding the different parts of a boiler and their functions is essential for homeown...

read article arrow Read Article
Baxi Boiler Error Codes

06th February, 2026 Guides

Baxi Boiler Error Codes

The complete guide to what each Baxi boiler error code means and how to fix it!

read article arrow Read Article
Floor Standing Boiler: Worcester Bosch Greenstar CDi Highflow Guide

06th February, 2026 Guides

Floor Standing Boiler: Worcest...

The Worcester Bosch Greenstar Highflow CDi series stands out with its floor-standing desig...

read article arrow Read Article
F75 Vaillant Error Code

06th February, 2026 Guides

F75 Vaillant Error Code

One of the most common and frustrating error codes your Vaillant boiler can present to you...

read article arrow Read Article
Moving Boiler To The Attic Or Garage

06th February, 2026 Advice

Moving Boiler To The Attic Or...

If you believe you would benefit from moving your boiler to a new location, either for fin...

read article arrow Read Article
Boiler Circulation Pump Replacement Costs

06th February, 2026 Guides

Boiler Circulation Pump Replac...

Here at iHeat we’re boiler experts, this includes an extensive bank of component knowledge...

read article arrow Read Article
Potterton Boiler (Combi Range)

06th February, 2026 Guides

Potterton Boiler (Combi Range)

Potterton are a brand with a celebrated lineage of expertise when it comes to heating, Pot...

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

06th February, 2026 Advice

What is an Immersion Heater an...

Everything UK homeowners need to know about immersion heaters and running costs.

read article arrow Read Article
Why Putting a Boiler Outside Is Often a Bad Idea

06th February, 2026 Guides

Why Putting a Boiler Outside I...

While putting a boiler outside may seem like a good idea to save space and reduce noise in...

read article arrow Read Article