I wired up a second AUX heater in the back bedroom. I ran the low and high speed fan wires from the AUX heater under the couch. The extra current draw from the second fan motor created too much heat in the rocker switch and burnt it out. I cannot get it to switch off now. The switch moves to the off position, but unless I hold it, it still sends power to the AUX heaters. The Low side still works properly, but I never use it.
If I can find a new switch I will use a relay so the power bipasses the switch.