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Copyright © D 262 -

12/08

Sketch the piping of the system. This is a relatively simple step that tends to be overlooked,
however it can often save hours of time in troubleshooting a system. Note flow directions in the
system paying close attention to the location of pumps, check valves, pressure bypass valves
and mixing valves. Ensure correct flow direction on all pumps. This is also a very useful step if
additional assistance is required.

Document the control for future reference. Before making any adjustments to the control, note
down all of the items that the control is currently displaying. This includes items such as error
messages, current temperatures and settings, and which devices should be operating as
indicated by the LCD. This information is an essential step if additional assistance is required
to diagnose the problem.

Isolate the problem between the control and the system. Now that the sequence of operation is
known and the system is sketched, is the control operating the proper pumps and valves at the
correct times? Is the control receiving the correct signals from the system as to when it should
be operating? Are the proper items selected in the menus of the control for the device that is to
be operated?

Test the contacts, voltages and sensors. Using a multimeter, ensure that the control is receiving
adequate voltage to the power terminals and the demand terminals as noted in the technical
data. Use the multimeter to determine if the internal contacts on the control are opening and
closing correctly. Follow the instructions in the Testing the Wiring section to simulate closed
contacts on the terminal blocks as required. Test the sensors and their wiring as described in
the sensor Data Brochures.

Monitor the system over a period of time. Select the applicable items in the Monitor menu of
the control and reset them to zero. Allow the system and the control to operate over a known
period of time and then record the Monitor items. Use this information to help diagnose any
remaining problems.

Sketch the

Piping in the

System

Document the

Control

Isolate the

Problem

Test the Contacts

Voltages &

Sensors

Monitor the

System

The highest recorded outdoor air temperature since this item
was last cleared. This can be used to diagnose if the Outdoor
Sensor 070 has been located correctly. If this reading is too
high, the 070 may be located in an area that receives direct
sunlight or is influenced by an exhaust vent. 

MODE = —1—

The lowest recorded outdoor air temperature since this item
was last cleared. This can be used to diagnose if the Outdoor
Sensor 070 has been located correctly. If this reading is too
high, there may not be adequate insulation behind the 070, or
there may be an exhaust vent nearby. 

MODE = —1—

The total number of running hours for Stage 1 since this item
was last cleared. This total time does not include the 

FIRE DLY

time set in the Adjust menu.

-67 to 149˚F
(-55 to 65˚C)

-67 to 149˚F
(-55 to 65˚C)

0 - 9999 

hr

 Section

262 

Monitor

 Menu (1 of 3)

LT

D

 

USER

 

INST

 

ADV

Range

Access
Level

Description

Item Field

Note

: To clear the recorded information in the specific 

Item field, press and hold   and  .

Summary of Contents for D 262

Page 1: ...ral energy saving features have been incorporated into the 262 such as Warm Weather Shut Down WWSD DHW post purge system setback DHW priority and an automatic differential for boiler operation LR 5823...

Page 2: ...available menu Once a menu is selected there will be a group of items that can be viewed within that menu Item The abbreviated name of the selected item will be displayed in the item field of the disp...

Page 3: ...in sec DHW 12 1 DHW Burner Displays when the stage 1 and or stage 2 relay is turned on Pump Displays when the boiler pump is operating DHW Pump Displays when the DHW pump is on Warning Displays when a...

Page 4: ...trolerrorisdeterminedusingProportional Integral and Derivative PID logic Proportional compares the actual supply temperature to the boiler target Boil TRG temperature The colder the supply water tempe...

Page 5: ...2 automatically determines the best differential as the load changes This reduces potential short cycling during light loads STAGE 1 2 STAGE The stage 1 and 2 setting may be selected to AUTO or OFF Wh...

Page 6: ...General Boiler Operation BOILER DEMAND A boiler demand is generated by applying a voltage between 24 and 240 V ac across the Boil Dem 1 2 terminals Once voltage is applied the Boiler Demand pointer i...

Page 7: ...viewed Atnotimedoesthecontroloperatetheboiler s above248 F 120 C WARM WEATHER SHUT DOWN WWSD OCC UNOCC RESET RATIO CHARACTERIZED HEATING CURVE When the outdoor air temperature rises above the WWSD se...

Page 8: ...encased in fins This type of terminal unit relies on the natural convection of air across the heating element to deliver heated air into the space The amount of natural convection is dependant on the...

Page 9: ...d to provide an external Boiler Demand as described earlier in Section B1 The zone control is capable of automatically adjusting the Boil TRG temperature to improve building occupant comfort and syste...

Page 10: ...TANK temperature and record the highest and lowest DHW TANK temperatures Also the 262 can control the DHW temperature with more accuracy than when using an aquastat DHW DEVICE DHW THRU Once the 262 re...

Page 11: ...s will be the only pump providing flow through the boiler s DHW PRIORITY OVERRIDE To prevent the building from cooling off too much or the possibility of a potential freeze up during DHW priority the...

Page 12: ...he 262 turns off the boiler pump P1 flow to the heating system must stop If flow is not stopped the temperature in the heating system can exceed the maximum desired temperature and can result in damag...

Page 13: ...rmally If a system override of AWAY is selected the 262 operates the SETPOINT load at the Occupied setting SETPOINT PRIORITY SETP PRI BOIL For setpoint loads to have priority over the boiler zone s se...

Page 14: ...l the Outdoor Sensor 070 and Boiler Sensor 071 according to the instructions in the Data Brochure D 070 and run the wiring back to the control If a DHW Sensor 071 is used install the DHW Sensor accord...

Page 15: ...ontrol These terminals are to be used as a switch to either make or break power to the DHW pump or the DHW valve Since this is an isolated contact it may switch a voltage between 24 V ac and 240 V ac...

Page 16: ...ernal timer tekmar Timer 032 or switch is used connect the two wires from the external switch to the Com and UnO Sw terminals 16 and 18 When these two terminals are shorted together the control regist...

Page 17: ...Power N and Power L terminals 6 and 7 the boiler pump should start If the pump does not turn on check the wiring between the terminal block and pump and refer to any installation or troubleshooting in...

Page 18: ...levels To lock the access level select the appropriate access level in the Miscellaneous Misc menu and move the DIP switch from the Unlocked position to the Locked position As long as the DIP switch...

Page 19: ...us Misc menu when the Lock Unlock DIP switch is set to the Unlocked position In the Advanced access level all of the control settings are available to the user In the User access level only a few of t...

Page 20: ...F 50 to 75 C This is the signal that is being received from a tekmar Zone Control 10K ZoIn MODE 1 35 to 110 F 2 to 43 C Current slab sensor temperature 10K SLAB MODE 1 Boil MIN OFF 58 to 167 F 50 to...

Page 21: ...8 00 hr Default OFF The maximum temperature at the slab sensor DIP switch Characterized Heating Curve No RTU connected 10K SLAB Boil MIN OFF MODE 1 The amount of morning boost DIP switch Characterized...

Page 22: ...eating system DIP switch Reset Ratio MODE 1 The time delay the control can expect between the time the boiler contact closes and the burner fires 0 00 to 3 00 min in 1 sec increments Default 0 10 min...

Page 23: ...hether or not DHW will be generated during the UnOccupied period DIP switch Setback DHW SENS NONE DHW THRU NONE OFF 100 to 220 F OFF 38 to 104 C Default 180 F 82 C OFF DHW XCHG Occ setting Default OFF...

Page 24: ...by the control S e c t i o n 262 Adjust Menu 4 of 4 The system s warm weather shut down during the UnOccupied period DIP switch Setback MODE 1 The maximum length of time that the boiler pump will con...

Page 25: ...0 sec ON Default ON ADV INST USER LTD Default INST The units of measure that all of the temperatures are to be displayed in by the control The operating mode for the back lighting on the LCD as well a...

Page 26: ...air temperature during an UnOccupied period for the heating zone Note There is only a 3 F adjustment in the LTD access level DIP switch Setback 35 to 100 F 2 to 38 C Default 65 F 18 C OFF 0 20 to 8 00...

Page 27: ...in the display turn on Step 1 The boiler pump Boil P1 is turned on for 10 seconds NOTE Only if there is a boiler demand can the control be paused in step 1 Step 2 The zccontact is turned on for 10 se...

Page 28: ...Boil P1 contacts are shut off NOTE Only if there is a boiler demand can the control be paused in step 3 Step 4 MODE 1 If a DHW Pump is selected as the DHW device the DHW Pmp Vlv contact is turned on...

Page 29: ...al contacts on the control are opening and closing correctly Follow the instructions in the Testing the Wiring section to simulate closed contacts on the terminal blocks as required Test the sensors a...

Page 30: ...that Stage 1 has had since this item was last cleared This item can be used in conjunction with the B1 FIRE item to determine the average cycle length of Stage 1 If the cycle length is too short a lo...

Page 31: ...he control and the RTU or RDM are run in a noisy electrical environment this can cause interference in communication between the control and the RTU or RDM MODE 1 3 to 40 min OFF Default OFF 0 255 0 2...

Page 32: ...st be ADV in order to clear the error The RTU was unable to read a piece of information stored in the Schedule menu Because of this the control was required to load the factory settings into all of th...

Page 33: ...is error message can be cleared once the sensor has been repaired To clear the error message from the control press either the Menu or Item button The air sensor in the RTU is being read as an open ci...

Page 34: ...ot connected to the control This error message can be cleared once the sensor has been repaired Locate and repair the problem as described in the Data Brochure D 070 To clear the error message from th...

Page 35: ...35 of 36 Copyright D 262 12 08 Notes...

Page 36: ...sub sequent to purchase which have not been authorized by tekmar or if the product was not installed in compliance with tekmar s instructions and the local codes and ordinances or if due to defective...

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