The IOM includes an operating pressures table as well as a water pressure drop table that can be used in combination with the table below for helping to determine root cause of your malfunction.
Refrigeration System Malfunctions and Probable Causes | |||||||
| Head Pressure | Suction Pressure | Compr Amp Draw | Superheat | SubCool | Air Temp Diff. | Water Temp. Diff. |
Undercharged system (leak) | Low | Low | Low | High | Low | Low | Low |
Overcharge system | High | High | High | Low | High | High | High |
Low Air Flow (heating) | High | High | High | Low | Low | High | Low |
Low Air Flow (cooling) | Low | Low | Low | Low | High | High | Low |
Low Water Flow (heating) | Low | Low | Low | Low | High | Low | High |
Low Water Flow (cooling) | Low | High | High | High | Low | Low | High |
High Air Flow (heating) | High | Low | Low | Low | High | Low | High |
High Air Flow (cooling) | Low | High | High | High | Low | Low | High |
High Water Flow (heating) | High | High | High | High | Low | High | Low |
High Water Flow (cooling) | High | Low | Low | Low | High | High | Low |
Low Indoor Temperature (heating) | Low | Low | Low | High | High | High | High |
Low Indoor Temperature (cooling) | Low | Low | Low | Low | High | Low | Low |
High Indoor Temperature (heating) | Low | High | High | High | Low | Low | High |
High Indoor Temperature (cooling) | High | High | High | High | Low | Low | High |
Restricted Filter/Drier | High | Low | High | High | Low | Low | Low |
Inefficient Compressor | Low | High | Low | High | High | Low | Low |
TXV – No Bulb Charge | Low | Low | Low | High | High | Low | Low |
Plugged Cap Tube | Low | Low | Low | High | High | Low | Low |
Scaled Heat Exchanger (htg) | Low | Low | Low | Low | High | Low | Low |
Scaled Heat Exchanger (clg) | High | High | High | High | Low | Low | Low |
Equalizer Line is Piped to Water Reg Valve | Works in the heating mode, but in the cooling mode, it pumps down the suction. | ||||||
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.