The 4 outputs for relays are:
- outdoor fan/ground loop pump
- indoor fan/hydronic loop pump
- compressor
- crankase heater/reversing valve
To make the reversing valve and the crankcase heater work together, off the same relay, they will both need to be active in heating mode. If they take different voltage, wire a transformer in.
This leaves room for customization. For example, if you wire your outdoor fan to the compressor, they will both run with each other. Then you can have a separate crankcase heater relay.