Too Hot or Too Cold: Two Common A/C issues

Common A/C Issue:  Unit is running, but no cool air is coming from the vents!

This is a frequent issue with two general items you can easily check yourself before arranging a service call.  The first thing you should do is check the furnace filter.  A dirty filter can restrict air flow to the A/C.  This can cause the evaporator coil to “freeze,” and possibly block all the air flow.  This causes the ice buildup to get worse.  If this is the case with your unit, you will need to shut off the A/C at the thermostat, change the filter, and then wait for the evaporator coil to thaw completely before using again.  This can sometimes take up to one day.  Check for water flowing at the outlet of the ¾” PVC drain line to see if the unit is thawing.  Now you’re ready to restart the system and see if the problem persists.

If this does not fix the problem, you may have a leak in the refrigerant system.  Low refrigerant pressure can cause the system to freeze over.  Some units have a low pressure, or “loss of charge” switch that will shut the system down until the refrigerant is refilled to the proper level.  You can try to check for loose valves or visible leaks, but a technician EPA-certified to handle refrigerant may be needed.

Common A/C Issue:  Too cold in the basement…too hot on the second floor.

This is a common complaint with most 2-story homes that depend on a single furnace and air conditioning system to care for multiple levels.

One way to help is to try setting the fan control switch on the thermostat to “ON.”  This enables the fan to run continuously, which keeps the air mixed and temperatures even.  It’s not hard on blower motor and if you have a furnace with a variable speed motor, the fan runs for just a few cents a day.  It should also be near silent.  However, if you do not have a variable speed motor, this can use quite a bit of electricity and can be noisy.

If the return air inlets in your home on the second floor are located low on the wall, you may want to consider relocating them.  A high position on the wall directly over the original location will pull the hotter air back into the system.  This also mixes it with air from different levels and rooms for a more even temperature throughout the house.  This is a good idea to keep summer and winter temperatures balanced.

One of the best ways to eliminate uncomfortable rooms is to install a ductless air conditioning unit in the space with uneven temperatures.  This keeps the temperature where you want it, in the space you need, without the whole house system over-working.  This is a much more efficient way to cool and far less frustrating than keeping the lower floor 10 degrees cooler just to be somewhat comfortable when you retire for the evening.