How hot does it get? 80°C should be enough to kill just about everything, albeit you would need to hold that temperature for a while. Boiling is a way to ensure (a) it has reached over 80°C, if you don't have a thermometer, (b) all of the water is at temperature rather than just a few localised hotspots, and (b) it is at or above that temperature for the few minutes it takes to heat up to 100°C and then cool back down, which gives the time necessary.
I don't have a coffee maker but I suspect it could work. You'd need to check more carefully than I have done for this post, though.
I just came across this
link which advocates low-temperature pasturisation.