Bear with me here, I am not very good at the DIY stuff. We do not have a traditional boiler. We have what I believe is just a water tank behind the fireplace and the fire heats the water. Now this is where I have been confused all along. I don't know how to get to the water tank/boiler. It must be right behind the fireplace - in the wall. How do I get to the water tank/boiler? Do I need to? We do have a couple of unmarked red knobs on pipes around the fireplace. Do these control anything?