NorAire NC-FE series, Installation & Operating Instructions Manual

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05/16/2014 33 NI216
Troubleshooting guide – these charts may help discern various refrigerant system conditions.
Troubleshooting Guide for NorAire “Heating”
Head
pressure
Subcool Suction
pressure
Superheat Compressor
Amp Draw
Water temp
differential
Undercharged system Low Low Low High Low Low
Overcharged system High High High Low High High
Low water flow High Low High High High High
Low return water
temperature
Low High Low Low Low High
High return water
temperature
High Low High High High Low
Blocked ODU fan or
coil
Low High High Low Low Low
Restricted filter/drier Low High Low High Low Low
Bad TXV / No Bulb
charge
Low High Low High Low Low
Troubleshooting Guide for NorAire “Cooling”
Head
pressure
Subcool Suction
pressure
Superheat Compressor
Amp Draw
Water temp
differential
Undercharged system Low Low Low High Low Low
Overcharged system High High High Low High High
Low water flow Low High Low Low Low High
Low AH airflow Low High Low Low Low High
Low return water
temperature
Low High Low Low Low Low
High return water
temperature
High Low High High High Low
Blocked ODU fan or
coil
High Low High High High Low
Restricted filter/drier Low High Low High Low Low
Bad TXV / No Bulb
charge
Low High Low High Low Low
Unit operating conditions – the ODU supplied service manual or decal will have temperature/pressure/
SH/sub-cool chart for the specific unit. This is required information after the line set has been installed
and the full system is charged. See Start Up section.