Hi, Norman and John,
Some time ago, after plugging my soldering iron leads into a 2 pin 3 amp socket to do the field chip job on a G11, deep in rural Suffolk, late one Saturday, I inadvertently burned out their earth leakage trip, leaving customer in the dark over one cold winter week-end.
Spent a while expecting a horribly expensive claim - not insured 3rd party at the time - lost some weight. Since then, thermal fuses and fuseable resistors have been my mantra.
As to central heating boilers - well, lots down at the tip. Just need a bit of welding for leaks at the bottom - design feature, I suspect - Chris.
PS Regret being thought feeble, but life in a phone box might give the wife some more reasons.