Hmm. I ment those surgical-like SureTouch things, but i suppose they're also a bad idea.
I built the thing in the attic, which is all wood and nothing to ground to. Managed to never touch the electronics though and no sparks were felt.
Is this mosfet on the heater board underneath the bed or on the main board?
I'll probably have to return only the defective part to the reseller as it is a DIY kit.