© 2019 tekmar 304V_D - 10/19
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User Interface - Indicator LED
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 re-
quires 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 through 4 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 to 4 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.
• Fuse 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.
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 to 4.
• 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 (valves closed).
Zone 1 Call
• On when thermostat 1 calls for heat.
• Off when thermostat 1 stops calling for heat.
Zones 2 to 4 Call
• On when the corresponding thermostat calls for heat.
• Off during priority operation.
• Off when corresponding thermostat stops calling for heat.
Zones 1 to 4 Valve Open
• On when corresponding thermostat calls for heat and the
zone valve is open (zone valve end switch closed).
• Off when zone valve closed (zone valve end switch open circuit).
• Off when corresponding thermostat stops calling for heat.
