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Low suction + high superheat (starved evaporator)

What is going on

Possible causes and checks for: low suction + high superheat (starved evaporator).

Likely causes

  • Low charge/leak, TXV bulb lost charge (valve closed), plugged drier

Check in this order

  1. Inspect bulb
  2. Replace TXV + liquid line drier
  3. Check oil for acid
  4. Recover/evacuate/recharge. (32E) p.878 [852]

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Source: General HVAC service practice — verify per model. Written in our own words; check the manual for your exact model.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.