The classic 50% rule (replace if repair > 50% of new) is too crude. A better decision tree combines age vs. category median lifespan, repair cost vs. residual value, recall status, and parts availability. Run these four checks in sequence and you'll get the right recommendation about 95% of the time.
Why the 50% Rule Is Incomplete
The 50% rule — "replace if repair cost exceeds 50% of new purchase price" — is widely cited and reasonable as a first approximation. But it ignores three factors that frequently flip the correct recommendation:
- Age relative to category median: A 14-year-old dishwasher with a $150 repair is statistically near end-of-life even though $150 is far below 50% of new price.
- Active recall status: A recalled appliance may have a manufacturer remedy that makes the repair question moot.
- Parts availability: A repair that costs $200 now may cost $0 in 6 months if the part goes out of stock permanently — making repair an increasingly poor investment.
The 4-Factor Decision Tree
Run these four factors in sequence. If any factor produces a clear recommendation, you can stop:
- Age vs. category median lifespan
- Repair cost as a ratio of replacement cost
- Active recall status
- Parts availability and future serviceability
Factor 1: Age vs. Category Median
Decode the manufacturing date from the serial number. Compare the appliance's age to its category median (see our full lifespan table):
- Age < 50% of median: Repair is almost always correct (unless Factor 2 or 3 overrides)
- Age 50–80% of median: Apply the 50% cost rule
- Age > 80% of median: Apply a stricter 30% cost rule — at this age, even a moderate repair rarely pays off
- Age > median: Default to replacement unless repair is trivial (<15% of new cost)
Factor 2: Repair Cost Ratio
The modified cost rule by age bracket:
| Age relative to median | Max repair cost as % of new |
|---|---|
| Under 50% of median | Up to 65% |
| 50–80% of median | Up to 50% |
| 80–100% of median | Up to 30% |
| Over median | Up to 15% |
Factor 3: Recall Status
Always check recall status before quoting a repair. If the appliance is under an active recall:
- Safety-hazard recall: Direct to manufacturer remedy first. Do not proceed with any repair until remedy is complete. The repair recommendation becomes moot.
- Non-safety recall: Disclose the recall, document, and proceed with the repair if the customer chooses. The recall remedy may address the problem without repair cost.
Factor 4: Parts Availability
For appliances older than 10 years, check parts availability before quoting. Key signals that repair is increasingly uneconomical:
- Control board is discontinued and available only from third-party sources at 3x original price
- Sealed-system parts (compressor, evaporator) require refrigerant certification and are priced near replacement cost
- Multiple repair quotes are needed to find a willing tech — indicating industry awareness that the model is end-of-serviceable-life
Worked Examples
Example A — Clear repair: LG dishwasher, manufactured March 2021 (age ~5 years; median 9 years = 55% of median). Door latch failure, repair quote $110. New unit cost ~$600. Ratio: 18%. Repair clearly correct.
Example B — Marginal: GE refrigerator, manufactured August 2014 (age ~12 years; median 13 years = 92% of median). Compressor failure, repair quote $850. New unit cost ~$1,200. Ratio: 71%. At 92% of median, max threshold is 30%. Replace.
Example C — Recall overrides: Samsung range, manufactured June 2019 (age ~7 years). Customer reports intermittent heating. Active recall covers this unit. Direct to recall remedy first — repair question is premature.
The Trade-Up Conversation
When replacement is the right call, the conversation can still be valuable. Identifying the right replacement appliance, flagging energy-efficiency improvements, and helping the customer avoid common buying mistakes is a service that builds trust — and generates referrals. Use the replacement recommendation as an opportunity, not an ending.