yeah its a lot of cool air with the fan on full and heat on full so from what you say a water problem? so that could be related to the pump? the pump def leaking coolant, my mechanic just told me to keep an eye on coolant level which luckly takes good month before i have to top it back up but long term prob going have to be replaced again which is annoying as its not a cheap job and i paid the earth for the repairs to get my car back to uk from ireland (nigbtmare) clearly got a dud part put into the car as well even though my mechanic says the water pump looks new, he trying to avoid repairs for me as he thinks car to old not worth spending money on it which is good of him but at the same time dodgy water pump is not good. all pipes been cleaned out infact my mechanic got heat working better than it was before from flushing the system out but its far from perfect.