[dsraven]

as a mechanic I have seen a lot of issues pertaining to maintenance of the cooling system. some I have pulled the block drains and nothing ran out the block had that much sediment. some I have had to remove the frost plugs and hose out the sediment it was so deep. overheating? dunno why...
backflushinhthe heater is also a good thing. if using a garden hose remember the domestic pressure is way more than a heater or rad core is meant to take. there are hose attachments to connect to overcome this. if you think your system is getting plugged up with blossoming etc use a coolant flush chemical first. go by the instructions. keep flushing until clear water comes out. collect the coolant because it's a eco hazard and you could find yourself paying a large fine if caught. as a firefighter I know the hazmat release would be cleaned up by proffessionals and the bill goes to you plus the fine. if it gets into a storm sewer or domestic sewer that clean up bill is huge.