I was brewing last night in me cellar, with a 40L boiler plugged into an extension reel. After a bit the power cut out and the extension socket was really hot (it’s got a thermal reset button on it if that is relevant).
So I had to move my boiler to a sub-optimal spot and plug it into the mains, and that worked fine as far as the power went.

Why is the extension reel not up to the job – is it something to do with its fuse not being big enough? Ideally I would like to brew outside, but it would be good to know what sort of extension cable I would need to buy to power the boiler. I guess the boiler must use a lot of power relative to most appliances?
Thanks for any advice, don’t really know the ins and outs of fuses, power etc.

Did you uncoil all of the extrension reel or was it still wrapped up in a tight bundle heating itself up and derating the cable?

Is it 13 amp rated ??
If so the breaker tripped because the extension overheated – ALWAYS unwind an extension lead FULLY if youre using that kind of wattage …

+1
If the cable was in a nice coil it’s gets all inducey and each loop affects the other.

You need to fully unwind the extension or it will cook itself.

It was all wound up nice and tight, yes 😳

Is it likely to be OK if it was all unwound? It is 13A rated.

If it’s a standard “plug in at the mains” boiler then it’ll be drawing less than 13 Amps. if the extension lead is rated to 13 Amps then you’ll be fine.

FWIW, my Dyson vacuum cleaner comes with clear instructions to fully unwind the mains cord before use.

The extension lead should have two ratings marked on it, one coiled and the other fully uncoiled. If you used it could up my guess is your boiler is above the coiled rating and that’s why it’s tripped out. Have a look on the boiler or in the manual to see if there is a power consumption figure quoted, then compare this to the ratings on your extension lead to see if it is upto the job