Install Instructions

19
SEQUENCE OF OPERATION
– NORMAL OPERATION–
(ALL DIP SWITCHES IN THE OFF POSITION)
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 for the zone valve end
•
switch to close, a red LED will illuminate, indi-
cating an open valve.
Once the zone valve opens the primary pump
•
is energized with 120 volts and the X-X contact
will close.
–
PRIORITY CHOSEN –
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 priority zone (zone 1) terminals 1 & 2 will
•
be energized with 24 volts.
The control will then wait for the priority zone
•
valve end switch to close, a red LED will illumi-
nate indicating the valve has opened.
Once the zone valve opens the primary 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.