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© 2011 

  D 538 - 12/11

Heating Operation

Section A

Sequence of Operation

When using only a room temperature sensor, the thermostat operates the heating 
system to maintain the Set Room Heat temperature. 
When using only a floor temperature sensor, the thermostat operates the heating 
system to maintain the Set Floor Heat temperature. In this case, the thermostat 
does not try to control the air temperature. This is ideal for bathrooms and some 
kitchen applications where the customer wants their feet to feel warm on the floor. 
This is also ideal for garages so that the heating system is not affected by the 
opening of the garage door in cold outdoor weather.
When using both a room temperature sensor and a floor temperature sensor, the 
thermostat always maintains the Floor Minimum temperature, even when the air 
temperature is satisfied. When the air temperature is below the Set Room Heat 
temperature, the thermostat operates the heating system to maintain the Set Room 
Heat temperature. The floor is never heated above the Floor Maximum setting in 
order to protect the floor covering.
The H1 symbol is shown on the display when the thermostat is heating. The heat 
can cycle on and off /- 1.5°F (1°C) of the Set Room Heat temperature.

Freeze Protection

 

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The thermostat operates the heat whenever the room or floor temperature falls 
below 40°F (4.5°C).

Exercising

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When connected to a tekmarNet

®

 reset control, the thermostat exercises the heat 

relay for 10 seconds every 3 days. Exercising helps prevent zone valves or zone 
pumps from failing due to precipitate buildup. During exercising, the thermostat 
shows “TEST” on the display.

Flushing

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The flushing feature is for open-loop systems that use a domestic hot water tank 
as a heat source. Flushing ensures that fresh potable water is circulated through 
the system once each day. If the thermostat is connected to a tekmarNet

®

 reset 

control with the Flushing feature turned on, the thermostat display will display the 
“FLUSH” icon for the duration of the flushing operation.

Hydronic System Supply Pump

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When connected to a tekmarNet

®

 system control, the thermostat’s Heat Supply 

Pump setting affects how the primary pump or mix pump on the system control 
operates. When connected to the boiler bus, the boiler system or primary pump is 
operated. When connected to the mix bus, the mix system pump is operated.
If the thermostat operates a motorized or thermal motor zone valve, the Heat Supply 
Pump setting should be set to On.

Summary of Contents for D538

Page 1: ...zation Zone Post Purge Intelligent setback Timer 033 Scenes Away override Auto Heating Cycle tekmarNet 4 communication compatible Requires 4 wires Pulse Width Modulation CSA C US Approved for use in U...

Page 2: ...ng the Thermostat Wiring 4 Mounting the Thermostat 5 Cleaning the Thermostat 6 Switch Settings 6 User Interface 7 Display 7 Button Operation 7 Symbols Description 7 Settings 8 14 Sequence of Operation...

Page 3: ...ire is 500 feet 150 m Strip wire to 3 8 10 mm for all terminal connections Use standard 4 conductor 18 AWG wire Installation Location Removing The Thermostat Base Push tab 1 Remove thermostat from bas...

Page 4: ...anager Connect the optional auxiliary sensor wires to the sensor terminals 5 and 6 1 2 3 4 tN4 Wiring Center or tN4 Zone Manager Slab Sensor 072 073 079 OR Outdoor Sensor 070 OR Indoor Sensor 076 077...

Page 5: ...should appear on the display 6 There should be continuity between the R 3 and W 4 terminals Testing the tekmarNet 4 Bus The symbol is shown on the display when communication is present If the thermost...

Page 6: ...back schedule as a schedule member if available Requires the installation of a Timer 033 to use this feature OFF OFF The thermostat does not follow a programmable setback schedule 2 ON SCENE The therm...

Page 7: ...GROUP The air group is cooling Heating can start once the cooling is finished LOCK Locked to User access level CLOCK Operating on a programmable schedule tekmarNet Communication is present WARNING SYM...

Page 8: ...ler SET ROOM HEAT AWAY Set the room heating temperature while in the Away scene Continued on next page Press and hold down both the and buttons for 2 seconds to change from one step to the next Releas...

Page 9: ...ng in the Adjust menu is set to Off 40 to 122 F 4 5 to 50 0 C Default 65 F 18 5 C Installer User SET FLOOR HEAT Set the floor heating temperature while in the event Available when A slab sensor is ins...

Page 10: ...rge number with Software Version upper right corner and the thermostat address 40 to 95 F 4 5 to 35 0 C Default 85 F 29 5 C Installer MAXIMUM SET ROOM HEAT Set the maximum room heating limit while in...

Page 11: ...n AND A slab sensor is installed on the auxiliary sensor input AND Sensor setting in the Adjust menu is set to Floor Off 40 to 122 F Off 4 5 to 50 0 C Default Off Installer User SET FLOOR MINIMUM Set...

Page 12: ...liary sensor input AND Sensor setting in the Adjust menu is set to Floor 1 2 3 4 Default 1 Installer SCHEDULE Thermostat can follow schedule master 1 2 3 or 4 Available when Switch setting 1 is set to...

Page 13: ...e tekmarNet system Choose Synchronize when zone heated using a boiler Choose Auto when zone is non hydronic heating Available when No reset control on the tekmarNet system ADJUST ADJUST OFF 1 to 16 In...

Page 14: ...t control mixing Installer tekmarNet ADDRESS The address is shown in the large number field Auto is shown in the upper number field when using automatic addressing Press the or the button to manually...

Page 15: ...the thermostat is heating The heat can cycle on and off within 1 5 F 1 C of the Set Room Heat temperature Freeze Protection The thermostat operates the heat whenever the room or floor temperature fall...

Page 16: ...r the group This thermostat can be set to be a member of the air group When operating as an air group the air temperature readings of all the air group member thermostats are communicated to the air g...

Page 17: ...e Display Room Temperature Setting 1 or or Follows programmable schedule or operates at the occupied temperature 2 Away Away temperature 3 Unoccupied temperature Scenes System Override Section E When...

Page 18: ...d BUS ERROR The tekmarNet 4 communication bus has either an open or a short circuit The result is that there are no communications Check for loose wires Check for short circuits between the tN4 and C...

Page 19: ...hort circuit error This error cannot be field repaired Contact your wholesaler or tekmar sales representative for details on repair procedures ROOM SENSOR OPEN CIRCUIT The built in air temperature sen...

Page 20: ...nsor was intentionally removed locate the Room Sensor setting in the Adjust menu and set to On Power the thermostat down and up to clear the error OUTDOOR SENSOR SHORT CIRCUIT The auxiliary outdoor se...

Page 21: ...clears after the auxiliary room sensor fault is corrected AUXILIARY ROOM SENSOR OPEN CIRCUIT The auxiliary room sensor has an open circuit Check for loose or damaged wires Locate and repair the proble...

Page 22: ...arly so that the room is comfortable at the scheduled time Pressing button does not increase temperature Flashing Max Installer can increase the Maximum Set Room Heat Flashing Floor Max Floor temperat...

Page 23: ...z 1 8 VA Standby 56 VA fully loaded NEC CEC Class 2 W Relay 24 V ac 2 A Sensors NTC thermistor 10 k 77 F 25 C 0 2 C 3892 Optional tekmar type 070 072 073 076 077 079 084 Job Record Jobsite Location __...

Page 24: ...s not cover the cost of the parts or labor to remove or transport the defec tive Product or to reinstall the repaired or replacement Product all such costs and expenses being subject to Purchaser s ag...

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