Residential Plumbing & HVAC Experts

A/C Acting Up? Troubleshooting Tips to Try First

Homeowners will be flipping the “on” switch on their thermostats as the weather warms up. Usually, things go as anticipated. But occasionally things just don’t go as expected. In many cases, a bit of A/C troubleshooting solves the problem but other times the problem warrants a visit from an HVAC service company. Read on for common problems and possible fixes.

  • The unit won’t turn on. The first thing to check is the circuit breakers at both the breaker box and at the outside unit. Turn it back on if it’s tripped. The next thing to check is the thermostat. Put in fresh batteries. It’s possible that it needs thermostat calibration. If a replacement is in order, an Energy Star rated thermostat is a good idea. If the unit has a condensate pump, be sure it’s not full.
  • If the larger copper line on the outdoor unit isn’t cold but the fan is running, the refrigerant is probably low. Call a service person to check for leaks and add refrigerant.
  • If there is some cooling but just not enough, check the temperature differential at two spots, where the air enters and where it exits the air handler. If it’s not between fifteen and twenty degrees, this is another indication of a refrigerant issue. If it’s much higher, try cleaning the blower wheel and evaporator coil. Also change the filter.
  • If the outside unit is making a loud buzzing, remove the panel from the outside unit and see if it is coming from the contactor (usually a square device with many wires coming out the top and bottom). Before replacing it, carefully label all wires.
  • Finally, if a brand new unit is the best way to go, select a high efficiency unit.

In many cases a problem can be fixed by the homeowner, saving money. The building code mandates that many tasks must be handled by a licensed professional. For more information on A/C troubleshooting, contact us.