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User Interface - Indicator LED
Power
• On when 115 V (ac) is applied.
• Off when power disconnected or transformer fuse is blown.
Priority
• On when zone 1 has priority over zones 2 and 3.
• Flashing while in priority override.
RoomResponse
TM
• On when modulating condensing boiler is operating
below maximum setting.
System Pump
• On when zone valve end switches are closed (valve open).
• Off when zone valve end switches are open circuit (valve closed).
Zone 1 Call
• On when thermostat 1 calls for heat.
• Off when thermostat 1 stops calling for heat.
Zones 2 and 3 Call
• On when the corresponding thermostat calls for heat.
• Off during priority operation.
• Off when corresponding thermostat stops calling for heat.
Zones 1 to 3 Valve Open
• On when corresponding thermostat calls for heat
and the zone valve is open (end switch closed).
• Off when zone valve closed (end switch open circuit).
• Off when corresponding thermostat stops calling for heat.
Sequence of Operation
Zone Operation
When a thermostat calls for heat by closing the R and
W terminals:
• 24 V (ac) is applied to the corresponding zone valve.
• The corresponding zone indicator LED is turned on.
Boiler Operation
When a thermostat calls for heat by closing the R and
W terminals:
• The boiler end switch XX is closed to fire the boiler.
This requires the control DIP switch to be set to
Master.
• The RoomResponse
TM
0-10 V (dc) or 4-20 mA signal
is sent to a modulating-condensing boiler.
DHW Operation
Many modulating-condensing boilers have multiple
temperature call inputs. Wire the DHW end switch to input
recommended in the boiler’s manual.
When a zone 1 calls for heat by closing the R and W
terminals:
• The DHW end switch is closed to fire the boiler at the
DHW temperature.
• The Mod Boiler output is changed to 10 V (dc) or 20 mA.
Priority Override
• The Priority LED light flashes when priority override is in effect.
• Priority for zone 1 is in effect for 60 minutes after
which priority override starts by shutting off zone
1 and resumes heating on zones 2 and 3 and
expansion zones.
• During priority override, the mod max dial setting
limits the RoomResponse
TM
signal to the boiler.
Master / Member DIP Switch
• Allows for unlimited expansion using additional
Switching Relays and/or Zone Valve Controls.
• The Master Switching Relay is wired and operates the boiler.
• If using a single Switching Relay set to Master.
• When using multiple Switching Relays and/or Zone
Valve Controls, set one control to Master and set all
other controls to Member.
• The boiler end switch XX only closes when the DIP
switch is set to Master and does not close when set
to Member.
T-Stat 1 Priority DIP Switch
When T-Stat 1 is calling for heat by closing the R and W
terminals:
• 115 V (ac) is applied to the Priority Pump 1.
• Zone 1 indicator LED is turned on.
• Priority indicator LED is turned on.
• Zones 2 and 3 zone valves and LEDs are turned off.
• Expansion Member controls shut off their zones.
• After 60 minutes of continuous zone 1 call for DHW
heating the control goes into priority override. This
prevents building freeze up if the DHW tank aquastat
fails in the closed position.
• A jumper wire must be installed on the zone 1 end
switch if a pump is installed and the Zone Valve End
Switches DIP switch is set on.
Exercising DIP Switch
• ON: Each circulator pump is energized for 30
seconds every 72 hours.
• OFF: Circulator pump exercising disabled.
Post Purge DIP Switch
• ON: After thermostat 1 stops calling for heat, the
zone 1 priority pump and zone valve remain on for 2
minutes to purge heat from the boiler to the zone.
• OFF: Post purge disabled.
Mod Boiler DIP Switch
Select either 0-10 V (dc) or 4-20 mA signal to the modulating
condensing boiler. Consult the boiler manual to determine
the signal type. The DIP switch position does not matter
if the modulating boiler output is not used.
System Pump During Priority DIP Switch
• On: System pump operates when zone 1 calls for heat.
• Off: System pump shuts off when zone 1 calls for
heat. Typically set off when using a pump for heating
a domestic hot water tank.
System Pump With Member Call DIP Switch
• On: System pump on the master control runs when a
zone on a member control calls for heat.
• Off: System pump on the master control does not
turn on when a zone on a member control calls for
heat.
Zone Valve End Switches DIP Switch
• On: System pump and boiler will not turn on until the
zone valve end switch is closed. Select this option
when using 3 or 4-wire zone valves.
• Off: System pump and boiler turn on immediately
when a thermostat calls for heat. Select this option
when using 2-wire zone valves.
Fuses
• All fuses are T5A 250V slow blow, glass 5 x 20 mm.
• Fuses 1 and 2 correspond to the 24 V (ac)
transformer power supply. If a fuse is blown, first
check that the thermostat wiring is not shorted. Then
replace the fuse.
