Washed Your Car Keys in the
Washing Machine?

It's the Most Common Key Death We See

We're Scarborough's mobile auto locksmith. We've cut hundreds of replacement keys over the years. And the single most common reason someone needs a new key — more than losing them, more than snapping the blade, more than theft — is washing the bloody things. It's always the same story: "I washed my car keys in the washing machine, I've panicked, what do I do?"

The good news: not every washed key dies. The bad news: most of them do, eventually. Here's what actually happens inside a key fob when it goes through a full wash cycle.

What the Washing Machine Does to Your Key Fob

A modern washing machine cycle is a brutal environment for a car key. Here's what it goes through:

• Soaking in 40°C water with detergent — water finds its way past the rubber seals and into the circuit board. Detergent accelerates corrosion on the copper traces.
• Spinning at 1,400 RPM — the key fob is thrown against the drum wall repeatedly, potentially cracking solder joints or the internal PCB.
• Hot water softening the glue — the fob shell starts to separate at the seams, allowing more water inside.
• Battery short-circuiting — the coin cell battery begins to electrolyze when wet, corroding the battery contacts and potentially leaking onto the circuit board.

Step-by-Step: What to Do Right Now

1. Remove the key immediately. The longer it sits wet, the more corrosion builds up. Fish it out of the machine — don't wait for the cycle to finish.
2. Remove the battery and battery cover. Pop the fob open if you can. Most fobs have a small seam on the side — use a flat screwdriver or a coin to gently prize it open. Take the battery out and set it aside (it's probably dead).
3. Shake out any visible water. Gently tap the fob against a dry towel, button-side down. Don't shake it violently — you could crack the PCB.
4. Dry it with silica gel — not rice. Rice works but leaves starch dust behind. Silica gel packets (the little sachets from new shoes or packaging) are better. Put the fob and a few packets in a sealed zip-lock bag for 24–48 hours.
5. After 48 hours, insert a fresh battery and test. Try unlocking the car first. If that works, try starting the engine. If the car cranks but won't fire, the transponder chip inside the fob may be damaged.

What NOT to Do (People Get These Wrong Constantly)

• Don't microwave it. We made an entire page about this. The metal in the key arcs, the chip fries, the battery explodes, and you have a melted lump of plastic. Read the full guide here.
• Don't use a hairdryer. The hot air pushes water deeper into the fob instead of evaporating it, and the heat can warp the PCB or detach surface-mount components. Room-temperature air circulation is fine; heat is not.
• Don't put it on a radiator. Same problem — heat damage. Your key fob's plastic shell warps at around 80°C. Radiators easily exceed that.
• Don't test it too soon. If there's still moisture bridging circuit contacts, powering it up will short the board and kill it permanently.
• Don't skip the spare key. If your washed key survives, great. But treat it as ticking clock — internal corrosion continues even after it's dry. Get a spare made while it still works so you're not stranded when it eventually fails.

Will My Key Survive the Wash?

Based on what we see in Scarborough every week: modern proximity smart keys (the kind with no blade you just have in your pocket) are the least likely to survive. The more advanced the electronics, the more fragile they are. Older flip-key remotes with a visible blade are slightly tougher — the key itself is fine, but the remote and transponder chip are often damaged. Traditional mechanical keys with an embedded transponder chip have the best survival rate, but the chip can still be unreliable afterwards.

Even if your key works after drying, the clock is ticking. Water that got inside the transponder chip's potting compound will continue to corrode the wire bonds over weeks or months. It might work today and fail next Tuesday, usually when you're parked in the furthest corner of a supermarket car park.

We Replace Washed Keys Every Day — Same Day, Your Location

If your washed key is dead, we'll cut and programme a new one at your home, workplace, or wherever you're parked — anywhere in Scarborough, Filey, Whitby, Pickering, Malton, and across North Yorkshire. We carry blanks and programmers for Ford, Vauxhall, Volkswagen, BMW, Mercedes, Audi, Toyota, Nissan, Peugeot, Renault, Honda, Hyundai, Kia, Land Rover, Volvo, and more. Response time is typically under an hour, and the replacement usually costs far less than the main dealer — and we come to you.