Cooler master says that the Seidon 240m is a maintenance free and sealed AIO cooler and IIRC they are giving a 2 year warranty. What happens after lets say, after 4 years (if one is still using the same cooler)? If needed how does one refill it with the coolant? I think the Eisberg has that option where you can refill the coolant reservoir, what about the seidon?