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Troubleshooting
DETECTING HVAC SYSTEM PROBLEMS
Symptom Possible Solution
DETECTING HEATING, COOLING AND FAN PROBLEMS
Symptom Possible Solution
Pressure switch open. Consult condensing unit
manual for possible cause.
Compressor is off due to internal overload protector.
Consult condensing unit manual for possible cause.
Condenser control board anti short cycle timer is not
yet expired. Most anti short cycle timers are 5 minutes
or less, if the unit does not start after 5 minutes consult
the condensing unit manual for possible causes.
Limit on furnace open. Check position of DAS in
the plenum and move further down stream if possible.
High static pressure must be corrected.
DAS limit jumper needs to be moved to a lower setting.
Trouble shoot air handler – see air handler
documentation.
Condensing unit receiving signal but will not turn on.
Air handler receiving signal but will not turn on.
A high static condition exists. Move the sensor
further down stream to sense air that has mixed more
thoroughly. Be sure not to place the senor past
the take offs. High static pressure must be corrected.
Bypass tap is too close to inlet of air handler.
Adjust bypass tap in the return air duct so that is further
away from the furnace. This will give the air more of a
chance to be tempered with room return air before
entering the air handler again.
Furnace tripped the primary limit, but the
zone panel does not indicate that the discharge
air limit has been exceeded.
No power to control panel. Green “Normal Flashing”
LED should be blinking. If not, apply power to 24VAC
inputs of control panel. Check fuse.
Single transformer system. Install jumper between RC
and RH at HVAC Equipment outputs of control panel.
Interlock switch on furnace is open – close access doors.
Thermostat is not calling for heat. Check voltage at the
thermostat W input on the control panel.
Thermostat is power robbing or mechanical. Only use
line powered electronic thermostat with a C terminal.
Zone panel set up to for Zone 1 mode control
and Zone 1 B terminal is not energized.
Check ZONE 1/ANY ZONE dip switch and check
for voltage at Zone 1 B terminal.
An open or short in the DAS sensor has been
detected. Install or repair the sensor.
Nothing comes on.
Heat will not come on.