Thanks all, I think I will give further thought to the location and make of heater.
On the subject of supporting Ukraine, I noticed on the Planar website that the Autoterm heaters were manufactured in Russia, so I gave them a call.
They told me the manufacturing company was Lithuanian/Latvian (I forget which) and up until the Russian invasion of Ukraine, the heaters were indeed made in Russia.
After the invasion, the company shut down its manufacturing operation in Russia and is now in the process of moving it out of the country.
Planar told me that the stock they hold was in the UK before the outbreak of war. So purchased when pretty much the whole world was buying Russian fossil fuels, timber products, vodka etc.