replacement alternative for Truth Lever Lock Awning Operator?

I see what you mean. This is definitely an issue. One thought is that you could use our 39-083 or 39-015 operators. These are made to work with more traditional crank handle that sticks up at a vertical angle, rather than a straight horizontal lever.I'm wondering if you where to use one of these operators along with a 39-114 handle and the 39-157 crank extension to clear the top of the heater cover. If this style operator is going to work, you'll also likely have to change the wood trim that goes over it. You may need the services of a carpenter to that end.

Also looking at your lower window sash rail, it appears to me that you could maybe pack up the existing operator a little. That's not a guarantee but it's easy enough to test out without having to buy new hardware. You might want to experiment with that a little. Just take note when moving the sash brackets that you don't go up so high that you will damage the glass when drilling new installation holes. While it may be an easier solution it does carry more risk.

We unfortunately don't sell an extension shorter than the 2" 39-337. A folding handle could work, but I'd imagine it'd be a little awkward to operate. Still, if the extensions won't do it then a folding handle is going to be your next best bet. See our 39-205.