HVAC Life Expectancy: When to Repair, When to Replace
Central air systems typically last 15–20 years. Use the $5,000 rule, the age-times-repair-cost test, and the SEER efficiency delta to decide whether to repair an aging HVAC or replace it.
Published 2025-01-18 · Updated 2026-04-21 · 4 min read
How long does a central HVAC actually last?
The ASHRAE service life guideline for residential central AC is 15 years; furnaces 18 years; heat pumps 14 years. In hot, humid Texas climates the AC end is typically pulled forward 2–3 years due to extended cooling-season runtime.
What is the $5,000 rule?
Multiply the system's age (years) by the repair cost being quoted. If the product exceeds $5,000, replace; if it is below, repair. Example: a 12-year-old AC with a $400 repair = $4,800 → repair. The same system with a $500 repair = $6,000 → replace.
What are the warning signs that a system is failing?
- Refrigerant top-offs more than once a year (likely leak in evaporator coil)
- Compressor cycling on/off in under 5-minute intervals (“short cycling”)
- Indoor humidity above 60% with AC running (under-sized or low charge)
- Electric bills rising 15%+ year-over-year with no usage change
- Visible ice on the suction line at the air handler
Is a higher SEER worth the cost?
For Texas, moving from a SEER 13 system to a SEER 16 system reduces cooling-season electricity cost by roughly 19%. At $0.13/kWh and 1,800 cooling hours/yr the payback on the SEER upgrade is typically 7–10 years for an average 2,000 sqft home. Above SEER 18 the marginal payback stretches past 12 years and is usually not worth it for an existing home.
How does ProActive score HVAC?
The HVAC sub-score on your Home Intelligence Score weights three things: current condition (filter, coil, drain pan, refrigerant), age vs. expected life (ASHRAE benchmarks adjusted for local climate), and open deferred items (any prior flagged finding). A 14-year-old AC with a clean coil and a flagged refrigerant top-off will score notably worse than a 14-year-old AC with no flagged items.
Frequently asked questions
How often should I change my HVAC filter in Texas?
Every 60 days during cooling season (April–October), every 90 days otherwise. Homes with pets or in pollen-heavy areas should swap every 30 days during peak season.
Is a heat pump a good idea in Central Texas?
Yes for new builds — modern variable-speed heat pumps handle the mild Texas winters efficiently and provide cooling. For existing homes with working gas furnaces, replacement timing matters more than the upgrade.
Does annual HVAC service really matter?
Yes — ENERGY STAR data shows annual tune-ups reduce HVAC energy use by 5–15% and extend system life by 2–4 years on average.