I can see your tank works perfectly below zero degree. But after reading through your screenshot I'm getting more confused why mine doesn't work. Our setting are quite similar.I noticed the only different setting from mine is Loop Min Flow. I' ve tried increasing the value to 1 like in yours (default is 0.05). But it doesn't help.The charge load is still 0, no assigned load of double duty chiller as well. I don't know. The other thing is the charge rate of your model is relatively small (9.1 MBtu/H equals to 760 RT I guess?) Have you tried any bigger number? I'm wondering if the tank still works with bigger chiller.One more question, did you give the charge loop a running schedule( though I've tried and it doesn't help either)?

Beside that, I'm also curious about your version number of Equest like Jenny.

Looking foward to your reply.