Roger Berke's site is no longer free; I think he was spending so much time at helping people online he opted for getting something for his trouble. That's OK since he knows his hydronics. But you should take Orman up on his offer, as he is our "resident" hydronic's expert. Just click on his name in his post above, and send him a message.
Butch is right, though. 3 motors wouldn't go out at once. There is likely a blown breaker or fuse in one common wire to them, or a common ground connection that's poor. I'll see if I have a wiring diagram somewhere that may give a clue where to look, though diagrams don't usually do that.
Joel
Addendum: no diagram found, but the manual indicates you should check the HydroHot control panel in the bay with the HydroHot. If any of the 5 "Heating Zone Status" lamps are red instead of green, you've had a short in that zone's circuitry; that means in either the thermostat or one of the heat exchanger units. If the Low Voltage lamp is lit red also, see if just resetting the controller does the trick: turn the Diesel switch off on the kitchen panel, wait a minute, and turn it back on.
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