"Dave W" wrote in message
news

It's ridiculous to imagine that mains quality has anything to do with your
wallpaper strippers failing.

Failing in what way? Permanently? Open circuit? Short circuit? Resettably?
What make & model?

If it is failing open or short circuit, that suggests that the element is
"burning out" - that its temperature is rising to a point that it melts and
either breaks or else makes contact with earth. Over-voltage would seem to
be a plausible cause of this. But with a large amount of water around it
(the water that the wallpaper stripper is boiling) and presumably good
conduction from the element wire to the surface and from there to the water,
I'd be surprised if over-voltage would cause *that* much of a temperature
rise.

Sounds an intriguing problem. I'll be interested to hear whether the mains
voltage *is* varying that much, if you manage to get a data logger working.