Install Instructions

20
SEQUENCE OF OPERATION
– PRIORITY PUMP CHOSEN –
In order to use the priority pump feature both the
zone valve/pump and priority dip switch must be
in the on position.
The control will scan all TT terminals looking for
•
a call for heat from any thermostat.
When a call for heat is detected on the priority
•
zone the green TT LED for the priority zone will
illuminate.
The jumper on terminals 3 & 4 of the priority
•
zone will result in the end switch being auto-
matically closed.
The priority pump is energized with 120 volts
•
and the X-X contact will close.
While the priority zone is calling for heat any call
•
for heat on zones 2 and above will be ignored
until the priority zone is satised or the priority
timer has elapsed. (See “Priority Timer” in this
manual for a more detailed explanation.)
If call for heat is detected on terminals 2 or
•
above when the priority zone is not calling the
control will operate as outlined above.
–
ZR-ZC –
The control will scan all TT terminals looking for
•
a call for heat from any thermostat.
When a call for heat is detected the green TT
•
LED for that zone will illuminate.
The corresponding zone terminals 1 & 2 will be
•
energized with 24 volts.
The control will then wait to for the zone valve
•
end switch to close; a red LED will illuminate
indicating an open valve.
The X-X terminal will be closed.
•
The control will wait for a signal back from the ZR-•
ZC terminals on the boiler aquastat. Once the sig-
nal is received the “ZC On” light will illuminate.