On the display
The control panel shows HIGH DISCHARGE PRESSURE FAULT. This exact wording is the only variant the manuals print, and the message appears in the unit's troubleshooting tables.
What it means
The manual's troubleshooting tables pair this message with four possible causes and give one corrective action for each. The causes cover the condenser fans, the refrigerant charge, air in the refrigerant system and the discharge pressure transducer.
Why it appears
- The condenser fans are stopped, or they run backwards.
- Too much refrigerant in the system.
- Air has entered the refrigerant system.
- The discharge pressure transducer is defective.
What to check
- Check the fan motor and the contactors, and confirm that the fan drives air upward.
- If the system holds too much refrigerant, remove refrigerant.
- If air is in the refrigerant system, evacuate the system and recharge it.
- If the discharge pressure transducer is defective, replace it. The manual's Service and Troubleshooting section gives the pressure/voltage formula to use.
Questions engineers ask
What causes HIGH DISCHARGE PRESSURE FAULT on a YORK YLAA?
The manual lists four causes: condenser fans that are stopped or turning backwards, too much refrigerant, air that has entered the refrigerant system, and a defective discharge pressure transducer.
What should I check first for HIGH DISCHARGE PRESSURE FAULT on a YLAA?
The manual's first action is to check the fan motor and the contactors and confirm that the fan drives air upward.
Can a bad discharge pressure transducer cause HIGH DISCHARGE PRESSURE FAULT?
Yes — the discharge pressure transducer is one of the listed causes, and the manual calls for replacing it. The manual's Service and Troubleshooting section gives the pressure/voltage formula.
What do I do if there is too much refrigerant or air in the system?
For too much refrigerant the manual says to remove refrigerant; for air in the refrigerant system it says to evacuate the system and recharge it.
Messages next to this one
Source
Written from the manufacturer's manuals for the YORK YLAA; every number and designation on this page is checked against them before publication. The row of the manual this message comes from:
All YORK YLAA messages: fault codes · YORK YLAA documentation · YORK manuals