Can a condensing unit that runs on R22 run on R410?

Sorry, but no. The pressure diffenece between 22 and 410 is extreme. You will need a new outdoor condenser, and matching indoor evap coil along with a new line set between the two. R22 condensers are not at all compatible with R410. Changing the expansion valve will do you no good. You will need a complete new system to have true functionality and reliability when switching from 22 to 410a. Hopefully some of the other pros here will come by and confirm this (or prove me wrong?) Plain and simple, the two refrigents use diffefent oils that aren't compatible (some will suggest flushing the system, but that is expensive, messy, and never truly cleans the system completley.) And your compressor is not built for the pressures demanded by a 410 system. Hope that answers your question. Over all, if you have someone tell you they can convert your old 22 condenser over to 410, kick them off the property right away.

NO!! And I agree with mygirlsdad77.

Good answer