The two quick rules
- The 50% rule: if a repair costs more than half the price of a new system, replacement is usually the better value.
- The $5,000 rule: multiply the system's age by the repair cost. Over ~$5,000 → lean replace; well under → lean repair.
Repair or replace, at a glance
| Factor | Lean toward repair | Lean toward replace |
|---|---|---|
| Age | Under 10 years | 15+ years |
| Repair cost | Minor, under half a new unit | More than half a new unit |
| Energy bills | Steady | Climbing year over year |
| Reliability | First real breakdown | Repeated repairs |
| Refrigerant | Standard, available | Old system on phased-out R-410A |
| Comfort | Heats/cools evenly | Hot/cold spots, can't keep up |
When repair is the right call
If your system is relatively young, the failed part is inexpensive, and it's the first real problem you've had, repair almost always wins. A well-maintained system that's simply had one component fail is worth fixing.
When replacement pays off
As equipment ages past 15 years, efficiency drops and breakdowns cluster. Pouring a major repair into an old, inefficient system often means paying twice, once for the repair, then again soon after for the replacement you needed anyway. A new high-efficiency system also lowers monthly bills and may qualify for rebates and tax credits.
Missouri timing tip
Peak summer humidity and winter cold snaps are when failures hurt most, and when rush decisions happen. If your system is mid-life, a shoulder-season inspection (and an honest second opinion) beats choosing under emergency pressure. For furnaces specifically, see furnace lifespan in Missouri; for cooling complaints, start with AC not cooling.
The refrigerant factor
Older ACs use R-410A refrigerant, which is being phased down in favor of lower-emission A2L refrigerants like R-454B starting in 2025. You don't need to replace a working R-410A system, but if you're already on the fence, the transition is worth factoring into a new install.
Get an unbiased answer
The honest truth: some companies push replacement because it's the bigger ticket. If you've been told to replace, get a free second opinion from Swiss Air first we'll give you the same recommendation we'd make for our own families.