tekmar 274 Boiler Control - Manual (Page 40)

© 2012 274_D - 11/12 40 of 44
Testing the Control
Test Press and Hold
for 1 second
The control has a built-in test routine that tests the main
control functions. The control continually monitors the
sensors and displays an error message whenever a fault
is found. The individual outputs and relays are tested using
a test sequence.
Test Sequence
Each step in the test sequence lasts 10 seconds.
Start the test sequence by pressing the Test button.
Pause the test sequence by pressing the Test button
again. To advance to the next step, press the Test
button again.
If the test sequence is paused for more than five minutes,
the control exits the entire test routine.
To advance to a particular step, repeatedly press and
release the Test button to display the appropriate device.
HAZARD
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Access to the Test button requires the removal of the
front cover and exposes hazardous voltage while the
control is powered. Only trained, qualified and competent
personnel should operate the Test button.
IF Boiler 1 = Auto
(repeat for each boiler set to Auto or CP1)
Step 4 If mode indicates that a boiler pump is used,
the boiler pump is turned on a remains on.
Next, the first stage of the boiler is turned on
and remains on. If a second stage is present,
the second stage is turned on and remains
on. If a third stage is present, the third stage
is turned on and remains on. If a fourth stage
is present, the fourth stage is turned on and
remains on. After ten seconds all stages and
the boiler pump are turned off.
Step 7 The DHW relay is closed.
The C.A. / Alert relay is opened.
The primary pump is turned off.
The control exits the test sequence.
If a device fails to operate during the test sequence, refer
to the installation section of this brochure to check the
operation of the control. If the control works properly,
refer to any troubleshooting information supplied by the
equipment manufacturer.
Max Heat
The control has a function called Max Heat. As long as
there is a demand for heat the control operates in this mode
for up to 24 hours or until the Test button is pressed. tN4
devices operate to meet their occupied setting +5°F (3°C)
and display the MAX segment to indicate the Max Heat
mode. Use this mode to run the circulators during system
start-up to purge air from the piping.
When a boiler demand is present the control targets
Boiler Maximum. If Boiler Minimum = Off, the control then
targets Boiler Design. This allows the Boiler Maximum
setting to be set higher for DHW generation.
When a DHW demand is present the control targets the
lower of Boiler Maximum or DHW Exchange.
The Boil Maximum setting and DHW Exchange setting
are always available in the Adjust Menu when in Max
Heat. The Boiler Design setting is also available in the
Adjust Menu when in Max Heat and the Boiler Minimum
is set to Off.
DHW priority and WWSD are disabled.
To enable Max Heat:
Press and hold the Test button for more than 3 seconds
and less than 6 seconds and the test LED will begin to
flash rapidly. MAX HEAT and TEST are displayed on
screen. No outputs are turned on until there is a demand
for heat present.
Test Press and Hold
for 3 seconds
To Cancel Max Heat:
Press the Test button to cancel Max Heat manually or wait
24 hours and the control will automatically leave the Max
Heat mode.
Zone Test
In Zone Test mode, each tN4 device can be individually
turned on one at a time. The control tests each zone for up
to 5 minutes of no button activity. Use this feature to purge
air out of each zone and assist in troubleshooting. No items
are available in the user interface of the control.
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Step 1 IF the RELAY item is set to ‘Damper’ or ‘Alert’
the C.A. / Alert relay is closed.
IF the RELAY item is set to ‘Alert’, the C.A. /
Alert relay is opened after 10 seconds.
Step 2 The Primary Pump 1 relay is closed.
IF Pump Sequencer DIP = On, the Primary
Pump 1 relay is opened after 10 seconds.
IF Pump Sequencer DIP = On
Step 3 The Primary Pump 2 relay is closed.