HELP!! Water in the bottom of my woodstove

Here in the Northeast (Mass) we have been receiving a LOT of rain. Woke up this morning to my wife saying we have water at the bottom of the woodstove. Took off the bottom louvre of the RSF Onyx fireplace and there was about 1/4 to a 1/2 inch of water! Worse yet, it caused some surface rust to develop on the bottom of the woodstove (the refractory has some black streaking on the back wall as well).

Any thoughts as to what may be causing the water to come in? Anyone else experiencing this??I have a vacustack cap fitted inside the ICC Class A chimney pipe rated for the stove. I am wondering if the cap is the problem. Storm collar looks ok from the ground (I am afraid of heights otherwise I would get up there) I cleaned up all the water and sanded the bottom of the steel lightly with some steel wool. I want to get this addressed before it does more damage. Any advice would be greatly appreciated!!

Thanks Mike! I am wondering if anyone has had any issues with vacustack caps and water penetration??

My other concern is with the surface rust that I took off. Does it harm the stove at all? There was some rusty water at the bottom of where the fan sits at the back as well. Don't know if the fan got damaged and I am wondering if I need a new blower fan or is the one that got wet ok? I would turn it on but it is connected to a rheostat and it is a bit humid and muggy to light a fire. ..

Thanks BB and EBL. I appreciate the quick responses. I will spray it with a light mist of PAM and see what that does. I can't believe this has happened. I love the stove and we depend on it for our primary heat so that blower is important for circulation. I have a call into a sweep that I know to take a look at that cap and see how it fits up there. My guess is that it may be a 6" cap in a 7" ICC chimney or something like that. This always seems to happen after it is cleaned. I wonder if the cap is being hit too hard from the bottom when it's cleaned out. I have had 2 different sweeps clean it and had the same issue last year.

I'm starting to wonder if I should have them put a bag around it. But I would think you should not have to with that type of a cap. I think it should be designed to keep out water. Disco, I don't think I have the problem with leaking that you have in that my stovepipe runs up a chase on the side of the house. I am going to attempt buying another vacustack cap with a spark arrester screen on it to see if it is the diameter of the cap that is the problem. If my sweep measures it and finds that it is 6" and not the required 7" I will have him replace it with the new one rather than try to load up the old one with caulking to seal out the rain. I hope that will correct the problem.