How much is too much to spend repairing something?

The familiar rule — do not spend more than half the replacement cost on a repair — is a rough proxy that works on a mid-life item and fails at both ends. A cheap repair on something already near the end of its life is bad value; an expensive repair on a well-made item with a decade left is excellent value. Turning both options into a cost per remaining year settles it properly and takes two minutes.

Step by step

1. Get a firm repair quote, including parts, labour and call-out.A diagnosis fee that is deducted from the repair is normal. What you need is the total to have the thing working, not the price of the part.
2. Estimate the remaining life after the repair, honestly.Take the typical life for that type of product, subtract its age, and reduce further if other components are the same age and equally worn. Repairing one part of a worn machine does not reset the rest.
3. Work out the repair cost per remaining year.Repair cost divided by remaining years. A £120 repair buying three more years is £40 a year.
4. Work out the replacement cost per year the same way.Replacement price, plus delivery, installation and disposal, minus what the old one is worth as scrap or spares, divided by the years a new one should last. Use the same method for both or the comparison fails.
5. Compare running costs across the two options.Where a newer model is materially more efficient, the running-cost difference over the remaining years belongs in the comparison, and on heavy-use appliances it can be decisive.
6. Check whether you should be paying at all.Manufacturer warranty, extended cover, an insurance policy, a bank account benefit, or your rights against the retailer for goods that were not durable. On a fault appearing in the early years, check rights before paying anyone.
7. Apply the tie-breakers.Repeated faults on the same machine, spares no longer available, safety-related faults, and the disruption of a second failure. Any of these pushes a marginal decision towards replacement.

Tips

• Repairs that replace a wear part with a known life — belts, seals, pumps, brushes, batteries — are usually good value. Repairs to control boards, sealed systems and structural parts are usually not.
• Get the fault diagnosed before deciding. "It might be the board" and "it is the pump" are different decisions and only one of them needs making now.
• Where a repair is marginal, its value rises sharply if you can do it yourself and the part is available. Check whether the manufacturer publishes spares and instructions.

Common mistakes

• Comparing repair cost with the cheapest possible replacement — The honest comparison is with an equivalent replacement, delivered, installed and with the old one taken away. Comparing a repair with a stripped-out budget model makes every repair look bad.
• Counting past repairs as a reason to keep repairing — Money already spent is gone. Past repairs matter only as evidence about future reliability — and as evidence they usually argue for replacement, not against it.

Questions people ask