On Fri, 10 Nov 2017 18:41:03 +0000, wrote:

On Fri, 10 Nov 2017 18:18:52 +0000, John Rumm
wrote:

n.

Note also that some heaters are configurable. I found some wall mounted
2kW fan heaters I ordered a while back actually ran at a default max of
1kW unless you set an internal switch to allow the full 2kW.

The ones like that I once looked after had the internal switch as a
rocker switch. A couple of small 2mm holes drilled opposite the switch
ends let me change them by using a small knitting needle poked through
the holes in a simlar manner to the way many battery powered amber
road works warning lamps used to be switched on/off using a matchstick
poked through a hole.

That could explain why dave only reads a max of ~1700W (1000 + 700W)
but I'm not sure how you would manage the 1300W down to 1000 (other
than the low voltage supply he mentioned).

I think it's just wired incorrectly or strangely, with the 700W
element not protected by the overtemp stat (because it alone would be
unlikely to take the rad to overtemp and said stat couldn't handle the
full ~200W)? shrug.

I assume there is still a thermal fuse in there providing the ultimate
overtemp protection?

Cheers, T i m