Any tips for removing stuck on heater flapper boxes?

[Burma-Shave]

Hi folks, I need to take one of mine off. The 3 bolts are off with no traumas thankfully, but even with these off, boy is that thing stuck on hard! Not even any sign of movement.

Any advice on this, I really don't want to wreck things digging around with screwdrivers and prybars trying to prise it off...cheers

[misteralz]

Is there space to get one of those rubber filter wrenches on it?

[Burma-Shave]

How would that work, it cant rotate because of the studs..?

[misteralz]

There should still be some movement - the thread of the studs doesn't touch the holes. You only need the tiniest of rotational movement and then, well, it's moving and you're on your way.

[sladey]

I'd be wary of heat as you're going to burn off corrosion protection

WD40, leave it. hammer gently on sides. Lather, Rinse, Repeat

then if no joy......

Tinsnips and cut them off (think you can buy stainless ones now)