Stove fan problem - suggestions?

Hey guys

I hope this is the right place to ask about this but apologies if not!

I've got a home made stove fan powered by a TEC/Peltier module, and it worked ok for a long time but was pretty weak so I built a new bigger one to get a better result.

This one uses 4x TEC modules (I think the code on them is 12706), with two series pairs connected in parallel (to double the voltage output, AND the current output).  So two pairs, with each pair in series for higher voltage, then the two pairs together in parallel.

It works, but after a while it slows down & stops.  I think the reason is the top half heatsink is getting too hot from the stove where it needs to be kept cool.

Problem is that i need these wide heatsinks both top and bottom in order to cover all 4 modules, so I'm not sure quite how to get round this problem?

Can anyone give any good suggestions on this please?

Many thanks!

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