Air Conditioners & Heat Pumps

Common problems for no cooling

Basic troubleshooting of generic problems. Details will be on model specific pages.

Problem	Solution
Filter too dirty. Biggest indication is low airflow.	Replace with new filter
Outside coil dirty	Wash outside coil with garden hose. Washing from inside out is best, especially when very dirty. When not too dirty, washing from outside in can be ok.
Inside Coil frozen	Turn off cooling, but keep fan set to "on" instead of "auto". Thawing can cause water leaks, start watchful and be prepared for the cleanup Can be caused by low air flow, low refrigerant levels, or low temperatures (inside or outside.)
Inside coil dirty	Clean inside coil with wire or nylon brush. Detergent and a light rinse may be required. Evaporator cleaner is preferred, but not required. Acidic detergents much be completely rinsed before further use. See model specific pages for details.
Inside or outside fan not working	most often caused by a failed motor. Ensure supply voltage is present at motor. Verify that capacitor is within tolerance. Power must be off and wires removed from capacitor to check. Replace motor as described in model specific page.
compressor not working	Most often caused by a failed motor, improper refrigerant levels, high temperatures If outside coil was washed, allow compressor to cool before restarting. If outside fan motor was replaced, allow time for compressor to cool before restarting. Ensure capacitor is within tolerance. Replace if needed. Allow time for compressor to cool before restarting. Check resistance between all 3 wires leading to the compressor. Power must be off and wires disconnected. See model specific page for details. Compressors are usually not worth replacing when not under warranty. Compressors that do not start with normal resistance readings and capacitor within tolerance can have life extended by adding "hard start kit". No guaranty of success.
improper refrigerant levels	check levels. Details in charging page If low, check for leaks. The leak must be repairs in many jurisdictions before refilling.