21
E SERIES INSTALLATION MANUAL
Description of Unit Operation
Heating Operation
Heat, 1st Stage (Y1)
The fan motor is started on low speed immediately, the loop pump is energized 5 seconds after the “Y1” input is re-
ceived, and the compressor is energized on low capacity 10 seconds after the “Y1” input. The fan is switched to medium
speed 15 seconds after “Y1” input. The hot water pump is cycled 30 seconds after the “Y1” input.
Heat, 2nd Stage (Y1, Y2) Single Speed Units
The hot water pump is de-energized, which directs all heat to satisfying the thermostat, and the fan changes to high
speed 15 seconds after the “Y2”input.
Heat, 2nd Stage (Y1, Y2) Dual Capacity Units
The compressor is de-energized immediately, the second loop pump is energized 5 seconds after the “Y2” input, and
the hot water pump is cycled 30 seconds after the “Y2” input. The fan changes to high speed 45 seconds after the “Y2”
input and the compressor is energized on high capacity 60 seconds after the “Y2” input.
Heat, 3rd Stage (Y1, Y2, W) Single Speed Units
The first stage of resistance heat is energized 10 seconds after “W” input, and with continuous 3rd stage demand, the
additional stages of resistance heat engage sequentially every 5 minutes.
Heat, 3rd Stage (Y1, Y2, W) Dual Capacity Units
The hot water pump is de-energized which directs all heat to satisfy the thermostat. The 1st stage of resistance heat
is energized 10 seconds after “W” input, and with continuous 3rd stage demand, the additional stages of resistance heat
engage sequentially every 5 minutes.
Emergency Heat
The fan is started on high speed, and the first stage of resistance heat is energized 10 seconds after the “W” input.
Continuing demand will engage the additional stages of resistance heat sequentially every 2 minutes.
Cooling Operation
In all cooling operations, the reversing valve directly tracks the “O” input. Thus, anytime the “O” input is present, the
reversing valve will be energized.
Cool, 1st Stage (Y1,O)
The fan motor is started on low speed immediately, the loop pump is energized 5 seconds after the “Y1” input is re-
ceived, and the compressor is energized 10 seconds after the “Y1” input. The fan is switched to medium speed 15 seconds
after “Y1” input (85% of medium speed if in dehumidification mode). The hot water pump is cycled 30 seconds after the
“Y1”input.
Cool, 2nd Stage (Y1, Y2, O) Single Speed Units
The fan changes to high speed (85% of high speed if in dehumidification mode) 15 seconds after the “Y2” input.
Cool, 2nd Stage (Y1, Y2, O) Dual Capacity Units
The compressor is de-energized immediately, the second loop pump is energized 5 seconds after the “Y2” input, and the
hot water pump is cycled 30 seconds after the “Y2” input. The fan changes to high speed (85% of high speed if in dehumidi-
fication mode) 45 seconds after the “Y2” input and the compressor is energized on high capacity 60 seconds after the “Y2”
input.
Fan(G only)
The fan starts on low speed. Regardless of fan input “G” from thermostat, the fan will remain on low speed for 30
seconds at the end of each heating, cooling or emergency heat cycle.
Lockout Conditions
During lockout mode, the appropriate unit and thermostat lockout LEDs will illuminate. The compressor, loop pump, hot
water pump, and accessory outputs are de-energized. Unless the lockout is caused by an ECM2 low RPM fault, the fan will
continue to run on low speed. If the thermostat calls for heating, emergency heat operation will occur.
Lockout modes of any kind can be reset at the thermostat after a 5-second waiting period, which restores normal
operation but keeeps the unit lockout LED illuminated. Interruption of power to the unit will reset a lockout without a waiting
period and clear all lockout LEDs.
