Okay: I know the correct answer to the question is "chuck it away and
get another one" but this is uk.d-i-y and I'd like to fix it if I can.

I think the thermostatic control (143211 086-6 printed on the component)
is worn out. The heater won't even switch on until the dial is up beyond
the 4 mark and regardless of the external temperature, switches off
after about a minute and won't come back on again for several minutes. I
can't find anything wrong with the rest of the heater so I'm guessing
the plastic bit that adjusts the bi-metal contact is worn out.

Where can I buy a replacement? I've searched rs-online and ebay without
result but maybe I'm not using the right search. And if I can't buy a
replacement, is there a near equivalent I could use? This one has spade
connector terminals so I think it should be easy to swap the part out.

Thanks,

Nick