That's what I was thinking. If you can get glass or PVC cut to fit, you can sandwich your UTH and thermostat probe between the wood and the sheet. You'll want to seal the edges to avoid any liquid seeping under. You'd also want to run the cables through the side rather than up the way you have them. One drawback is it would be difficult to replace the UTH or probe if needed. Just a thought - may be more trouble than it's worth.
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