It's standard procedure around here to to install a receptacle for the AH. 9 times out of ten it's a 120V unit mounted in the attic. The HVAC guy puts a pigtail on his unit and it can be tested (or run for temp heat) with an extension cord if he gets his job done before I get there.
Another benefit is that the HO can also run it from an extension cord for troubleshooting purposes or by portable genny in an outage.
Falls under the keep it simple rule as I see it.
