The boiler is part of the cooling loop – it is really one unit. If the flame is heating the boiler but your not getting cooling there is a fair chance the cooling unit is in need of replacement. They are not repairable. I suggest doing some research on cooling unit replacement if you want to consider doing this yourself. There is a lot of good information out there to help you diagnose the issue. I just replaced our cooling unit with great results. Half the cost of a new refrigerator and not at all hard to make the swap.