The compressor on your central air conditioning unit is responsible for pumping refrigerant and triggering the start of the whole cooling system. Problems with the compressor can lead to less refrigerant entering the system, which can impact efficiency, or keep the unit from cooling at all.
There are a few common compressor problems that can affect a central air conditioner. Here are a few of the potential causes – and how you or an air conditioning repair technician can fix the problem.
Compressor Won't Turn On: Thermostat or Control Board
It is pretty simple to tell if the compressor isn't turning on at all. Turn down your thermostat, walk outside, and stand next to your air conditioner's condensing unit. Is the unit quiet? Your compressor likely isn't turning on.
There are two potential fixes for this problem: One you can fix easily on your own, and the other is a more complicated issue requiring an HVAC tech.
The easy fix is to check your thermostat. Are the settings correct? Is the thermostat turned to cooling and the temperature for a number lower than the current temperature inside? Have you changed the batteries recently in the thermostat? Note that dying batteries can mess up the functionality of a thermostat long before any actual display issues begin.
If the thermostat looks to be in order, you want to call in an HVAC tech. Your control board malfunction can be due to electrical problems in the capacitor or compressor itself. Checking and changing those parts should be left to someone who knows how to properly handle the equipment, or you can completely ruin your cooling system.
Compressor Won't Turn Off: Thermostat or Dirty Coils
Thermostat issues can also make the compressor run all of the time, so, again, make sure the settings are correct and that the batteries are changed.
Compressors can also run excessively due to dirty condenser coils, which are easy enough to clean on your own. Turn off the power to your outside condensing unit using the nearby fuse box. Remove the upper lid of the unit, which should be attached with either flipping latches or screws.
Once the lid is removed, look inside and locate the coils on the interior wall. Those are the condensing coils, which convert gas refrigerant to liquid. Use a hose to spray the coils clean. Make sure you aim the water from inside the unit at a somewhat downward angle so that any excess water ends up on the exterior ground rather than the bottom of the unit.
Reattach the lid properly and restore power before checking your unit for functionality.
For more extensive issues, contact a professional HVAC contractor, like those at Daniel's Heating Air & Plumbing Inc.