tekmar 401 House Control Installation User Manual
Page 27
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© 2011
D 401 - 07/11
Symptom
Look For...
Corrective Action
LCD display is off
Fuse holder
Control power supply has a 24 V (ac) fuse which if blown, requires
replacement.
Power to control
Use electrical meter to measure 24 V (ac) voltage on input power R and C
terminals.
No central
heating
Burner symbol on
LCD
If the burner symbol is on the LCD, there is a problem with the boiler. Ensure
the boiler aquastat manual limit is reset to the on position.
WWSD symbol on
LCD
Warm Weather Shut Down (WWSD) is an energy saving feature that prevents
central heating during the summer. Ensure the outdoor temperature reading
is accurate and replace outdoor sensor if necessary. WWSD setting can be
increased if heating is required.
Boil Calls on LCD
If there are no Boil Calls, there are no thermostats calling for heat.
DHW Call on LCD
During DHW tank heating, the central heating may not be heated.
System in AWAY
During AWAY, the thermostats operate at a lower temperature. Locate a ‘User
Switch’ and set to Normal to resume heating.
Single zone over
heating
LCD shows zone on
Thermostats have a differential of +/- 1.5°F of the temperature setting. Due to
the display rounding numbers up, heating can appear on when the temperature
is 2°F above the setting. This is normal operation.
LCD shows zone off
Ensure zone pump terminals measure 0 V (ac). Measuring 0 V (ac) indicates
the control relay is functioning correctly and the problem may be related to
the mechanical piping. Measuring 115 V (ac) indicates control relay may have
failed.
Single zone under
heating
LCD shows zone on
Ensure zone pump terminals measure 115 V (ac). Measuring 115 V (ac) indicates
the control relay is functioning correctly and the problem may be related to
the mechanical piping. Measuring 0 V (ac) indicates control relay may have
failed.
LCD shows zone off
Check for Boiler Call
Frequently Asked Questions (2 of 2)
Item
Setting
OUTDOOR DESIGN
BOILER TYPE
BOILER DESIGN
BOILER MINIMUM
BOILER MOTOR
MINIMUM MODULATION
MODULATION DELAY
WWSD OCCUPIED
WWSD UNOCCUPIED
Item
Setting
DHW MODE
DHW EXCHANGE
DHW OCCUPIED
DHW UNOCCUPIED
SETPOINT
UNITS
Job Record