Many years ago – possibly following link from this forum – I bought a stove fan – the requirement was listed overhead clearance, as it sat in a low fireplace. Mission accomplished its ran fine until recently – doesn’t trigger.

Think it was Chesire designs – has a wooden centre piece on the fan, 8 bladed, the heat sink is like something out of a computer stack. Solid machined base unit. Anyone know where it might be repaired, or have experience of fixing such kit?

Try a new teg, they are just 2 or 3 quid. Some thermal paste smeared on it’s sides helps, to another couple of quid.

Is a TEG another name for the Peltier device? I’d agree with changing it anyway, they don’t like overheating and a low profile stove fan is probably more susceptible to overheating.

My standard fan has a metallic strip under the base, if it gets too hot it starts to bend down and lifts the base of the fan slightly (and usually starts making a quiet rattling noise)

Yes although most of the cheap ones are actually peltier, designed to have current passedv through and cool one side. They work as, and are used here as a teg, Thermo electric generator

I have no idea how to go about sourcing or replacing one I’m afraid! My soldering days such as they are are well behind me.
It’s almost certainly overheated, stove is used much more this winter than in last few years.

Might have to ask around locally or see if anyone on local groups has expertise that is beyond me.