Care And Cleaning; Troubleshooting - Quest Controls BACnet T­Stat User Manual

7.0 Care and Cleaning
The BACnet T‐Stat should provide years of uninterrupted service. Minimal preventive maintenance is
required. However; it is important to make sure that the T‐
Stat is kept free of dust. A dusty T‐Stat will not allow air to
circulate properly around the built‐in temperature sensor
effecting proper operation of the unit.
8.0 Troubleshooting
LCD Screen is dark and no characters are
displayed
T‐Stat mode say Cool1, but compressor
does not engage
Clock loses time after power failure
Buttons do not respond
Display is corrupted
BACnet T‐Stat User's Manual Rev 1.1, 7/28/11
Remove cover and verify presence of power on the "R"
terminal, check connection of the common on the "C"
terminal. Check for presence of 24VAC between R and C.
Verify connection to HVAC unit. Ensure short‐cycle timer is
not inhibiting unit.
Replace the CR1025 Lithium battery
Press buttons slowly, some functions may take pressing the
button twice.
First, cycle power to the unit. If this does not correct the
problem, reset system by removing the T‐Stat body from the
mounting plate. Then return the body to the mounting plate
while depressing the up arrow, center button and down
arrow all at the same time. The display will respond with
"Cold Sense", these buttons must be held for a minimum 5
second. This will begin a
system restart and the
display will respond with
"Cold Start". Release the buttons at this time. This action
will reset the T‐Stat and return all settings to their factory
defaults. All custom schedules will be erased.
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