..but if I ask on here what could possibly go wrong?
Tumble drier & washing machine are both connected to a double extension lead (& have been for years) The 13amp fuse has blown in the plug of the extension lead and on closer examination there is a tiny scorch mark inside the plug, where the fuse fits in. The question is, should I just replace the fuse & merrily carry on? Is the scorch mark normal if the fuse gives up the ghost and do fuses just fail without there being an underlying problem?
Answers below please, preferably with an indication of whether or not you know what you are talking about 😉

ta

Sounds like an overload to me.

Just put a 6 inch nail in instead, cut down to size, obvs.

No, IANAE.

If you’re drawing around 13 amps through a single plug, it can easily overheat the plug without blowing the fuse. Best with separate supplies.

replace and if it blows again then test

Switch on one item at a time and see what happens

Is the extension lead coiled up? Have you ever felt the temperature of the coils when both machines are running?

Tiny scorch in plug – could be from fuse going, or from the intermittent overloading it’s probably had at times when both appliances are running and drawing a lot of current.

A 13A fuse (any wire fuse) doesn’t have a sharp cut-off. Most will probably never blow at 14A; at 20A it’ll probably take hours; at 30A probably a few seconds to minutes; at 200A under a second. Been a while since I looked at the numbers, so these may be a bit off, but you get the idea – the fuse won’t normally blow if you overload it a bit, for a short time.

As mentioned above, plugs / wiring may get quite warm at times with your setup. Try and find the rating plates on the back of the appliances. These will tell you the total power (watts, W or kilowatts, kW) and current (amps, A) required by each.

If the total for the two appliances is more than 13A, or 3000W (3kW), then running them both from a single extension is not a great idea.

How much hassle would it be to run a second extension?

I’d look to improve the set up. I used to run our washing machine and microwave from a cheap extension lead. Worked fine for years. When I moved it once I’d finally got round to sorting the kitchen it wouldn’t unplug. I opened up the extension lead and the internals had melted and fused. Could’ve been quite nasty but we were lucky. At least run 2 leads, and reasonable quality ones the correct length.

Based on our machines, a traditional vented tumble drier and a cold fill washing machine are about 3kW each, which is 13A each, so overload is my guess.

Yes, you’ve got two high current draw appliances connected to one 13A outlet. That’s dangerous and you could start a fire.

Don’t fuses have a service life?
Even if a fuse never reaches it’s rated failure current/heat, repeated heating and cooling cycles will eventually cause it to fail anyway.
Replace it like for like and the new one will probably last about the same time.
Although, as others have said, running two 13A appliances through one 13A fuse is probably not a good idea and you’ve just been lucky up until now.

IANAE.

You’ve got a set-up that could potentially burn your house down. You’ve just had a warning shot from it. Your call but fixing the problem seems a better option than patching it up.

You gotta ask yourself a question. “Do I feel lucky?”

Well, do ya?

you need this graph:

Lower bound for 13A Fuse
0.01s @ 100A
0.1s @ 50A
1s @ 30A
10s @ 25A
100s @ 23A
1000s @ 21A

Upper bound
0.01s @ 400A
0.1s @ 130A
1s @ 30A
10s @ 55A
100s @ 40A
1000s @ 28A

So, two 13A loads could run in parallel for minutes without tripping a 13A fuse, which would stress the cable & plug a little bit (but they’re also rated above 13A for sustained loads).

Try packing dried leaves and torn up newspaper around the plug.

I’m a time served electrical fitter. But not a very good one.

Can you add additional wall sockets? But before you do, have a look inside the existing socket to see if it’s connected to the ring main (2 wires of each colour going in and out is a good but not foolproof test) or if it’s on a spur (just 1 wire).

Try packing dried leaves and torn up newspaper around the plug.

I’m a time served electrical fitter. But not a very good one.

I reckon you need some form of liquid based cooling system using, say petrol, as the coolant. Rig up a pump, which cools the plug with a steady stream of petrol….

I just woke up this morning to a fire in my kitchen, probably caused by an electrical fault in the cooker hood. My advice: get it sorted properly!!!

have a look inside the existing socket to see if it’s connected to the ring main (2 wires of each colour going in and out is a good but not foolproof test) or if it’s on a spur (just 1 wire).

Meaningless if it was installed by someone who thought a spur of a spur was a good idea. All two wires tell you on their own is that two wires pass through, nothing more.

If it’s in the main part of the house, on an original wall amd with original fixtures (pattress box and conduit) then the chances are good that it would indicate a ring main. As soon as any modifications (extension, partition wall, new fixtures) enter the game all bets are off.

Source: time served householder with a right twunt for previous occupant.

a right twunt for previous occupant.

is there any other kind ?

you’re not just drawing the amperage of the appliances if using a coiled up extension, the coils are creating their own emf which is increasing the load, hence previous post about coils melting. run 2 extensions, fully unwound

Thanks for the advice everyone. Now running the two appliances on separate plugs 🙂