Let me jump in here-- What do you mean by "control lever"? The top lever is MAX-FRESH-OFF-HEAT-DEFROST.. Where is "full on"?The lower lever is MIN-MAX...Where is "full on"? If you put the vacuum gauge on the hose to the water valve, MAX-FRESH-OFF will give you nothing with a working system. If you put the vacuum gauge on the water valve, HEAT-DEFROST will show a reading controled by the lower lever MIN-MAX. Low reading at MIN and higher reading at MAX. On the AC side vacuum goes to the AC thermostat switch.There is no "mixing" with these systems, only temperature control for the flow of hot water or for cycling the compressor. No vacuum to the water valve should give you no heat. It sounds like you are supplying full vacuum at all times. Harley (
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