Boiler Repair vs Replacement — How to Decide

The £500 Rule of Thumb

A commonly used guideline: multiply the boiler's age by the repair cost. If the result is over £500, replacement is likely more economical. For example, a 10-year-old boiler needing a £60 repair: 10 × 60 = 600 — probably worth replacing. A 4-year-old boiler needing the same repair: 4 × 60 = 240 — worth repairing.

When to Repair

Repair makes sense when:

• The boiler is under 7–8 years old
• The boiler is still under manufacturer's warranty
• The repair cost is below £300–£400
• This is the first significant breakdown
• Parts are still readily available

When to Replace

Replacement makes sense when:

• The boiler is 10+ years old
• Repair costs exceed £500
• You've had two or more breakdowns in the past two years
• The efficiency rating is below 90% (costing extra on energy bills)
• Parts are discontinued or difficult to source

The Energy Savings Calculation

Modern A-rated condensing boilers operate at 92–94% efficiency. An older boiler running at 75% efficiency on a £1,200/year gas bill wastes around £240 per year in comparison. A new boiler installation at £2,500 could pay for itself in energy savings within 10 years — before accounting for reduced repair bills.

Get an Honest Assessment

Call us for a free assessment. We'll tell you honestly whether repair or replacement makes more sense for your specific boiler and circumstances — without trying to upsell you on a replacement you don't need.