Cost Comparison Overview: The £3,200-£4,250 Question
Let's start with the bottom line: replacing a boiler privately costs £2,500-£4,000 on average in the UK. This isn't just the boiler unit—it's the complete package including installation, system flush, Building Control notification, disposal, and warranties. Through ECO4, qualifying households receive this exact same package at zero cost.
After analyzing 7,000+ installations over 12 years, I can confirm the £3,200 average saving is real and consistent. Here's the detailed breakdown most installers won't show you upfront:
| Cost Component | Typical Range | ECO4 Free | Paying Privately |
|---|---|---|---|
| A-rated boiler unit | £800-£1,500 | £0 | £1,200 |
| Gas Safe labor | £800-£1,200 | £0 | £1,000 |
| System flush/upgrades | £200-£400 | £0 | £300 |
| Building Control | £150-£300 | £0 | £200 |
| Old boiler disposal | £100-£200 | £0 | £150 |
| Loft/cavity insulation | £600-£1,000 | £0 (included) | +£800 |
| Smart heating controls | £150-£350 | £0 (included) | +£250 |
| TOTAL PACKAGE | £2,800-£5,050 | £0 | £3,900 |
The financial advantage is undeniable: ECO4 provides a £3,900 value package at zero cost. Paying privately means spending £2,500-£4,000 for the basic boiler (without insulation/controls) or £3,900-£5,000 for the full equivalent package. That's 40-50 months of typical post-upgrade heating bills (£70-80 monthly)—essentially 3-4 years of free heating.
Free ECO4 Boiler Benefits: What You Actually Get
ECO4 isn't just a "free boiler"—it's a comprehensive home energy efficiency package that typically includes more value than paying for a boiler alone. After guiding 7,000+ installations, here's what qualifying households actually receive:
Paying for New Boiler Advantages: When It Makes Sense
While free ECO4 is objectively better value for qualifying households, paying privately does offer specific advantages in certain situations. Here's an honest assessment of when paying makes sense:
Check Your ECO4 Eligibility Now
Complete our 2-minute assessment to see if you qualify for a free boiler upgrade worth £2,500-£4,000.