It's not any preconceived time limit. e.g if you bought a fridge, a reasonable time for a consumer guarantee would be around the 10 year mark. I would expect that fridge last for a reasonable time, to me, that would be around 10 years. When making a claim, it's "reasonable time" is judged case by case. I've had a colleague at an old work place go through a consumer guarantee claim for a washing machine, it was the top brand that prides themselves on their product performing and lasting longer than others.. In the end, they supplied the parts, but expected the person to pay the labour (as that is not their issue, rightfully so) to have the machine fixed. Not always going to be the result you want, but there are guarantee's in Australian consumer law for this reason.