Automag Relay Question

UPDATE: All is working as it should. Transformer fuse seemed to have been the issue. I am thinking I blew the fuse as I was replacing one of the zone valve heads, or when fixing some loose wiring on the control board. Initially I think It may have a been one bad coil and as I was replacing it I may have blown the fuse, which then lead to the all zones failed open scenario. That relay was not receiving power, which then made the DHW tank thermostat not be operational.

Thanks so much for all the input, I very much appreciate it and it has helped get a better understanding of this system.

Agreed. I redid the wiring with new connectors on the relay. I plan to redo the wiring on the main board this summer. Thanks again!