Is it worth repairing, or should you replace it?

Nearly every page that answers this reaches for the “50% rule” — don't spend more than half the price of a new one. That number traces to no identifiable original source, and it is frequently credited to ENERGY STAR, which does not publish it. ENERGY STAR's actual guidance is an age-and-condition checklist. We don't use the rule, because we don't have to: we hold the measured annual energy use of the specific machine, so the comparison can be done with real numbers.

How we work it out

1. What the repair costsThe live price of the part your symptom points to, not a national average. Labour is extra if you're not doing it yourself — a service call runs roughly $75–$150 before parts.
2. What the machine costs to runIts own DOE or ENERGY STAR measured figure, from the certification registry — not a category estimate.
3. What would replace itTwo figures: the median of current models in the same configuration, and the best available technology. These are usually very different answers.
4. How many years it has leftExpected service life from the 2021 NAHB / Home Innovation Research Labs study, minus its age.

The finding that surprised us

Running this across our corpus, replacing a mid-life appliance with a typical new one saves almost nothing — about $8 a year on a refrigerator, and on one vented dryer we measured, marginally less than nothing. The efficiency floor has moved so little that like-for-like replacement is rarely an energy argument.

The gap only appears on a change of technology. A heat-pump dryer against a vented one is roughly $64 a year. So the honest advice is usually: repair it — and when you do eventually replace it, what you replace it with matters far more than when.

Try it on a machine

Full calculator across the corpus is next — these two have the complete data wired.