WHY ISN’T MY COOLING SYSTEM RUNNING WHEN MY THERMOSTAT IS SET TO COOL?
If you’re signed up for a Saver’s Switch through your utility company or a Demand Response program, your Air Conditioning compressor may be cycling off for longer intervals. This occurs during peak demand hours. If that’s not the case, try the following steps:
- Verify that the thermostat is switched to cool mode and has a cooling set point below the room temperature reading.
- Check the thermostat display for cooling, usually indicated by the words “cool on” or a snowflake icon. If these icons are flashing, the thermostat is in delay mode, which can last up to 5 minutes. This delay protects your equipment from short cycling.
- If the thermostat is set for cool, verify that the furnace door is securely closed and that the furnace’s power switch is set to On.
- Make sure the furnace circuit breaker switches are on.
- In most cases, your thermostat turns on the compressor and fan (Y and G terminals/ wires) during cooling.
Remove your thermostat faceplate. Verify these wires are firmly connected to the correct terminals.
If the cooling still doesn't come on, but has worked in the past, call a professional HVAC contractor to assist you.
- Verify that the wiring was matched correctly from the old thermostat to the new thermostat. If there are no separate wires to R and Rc, these terminals must be connected. On some thermostats, this connection is made by a jumper wire connection; on other models this connection is made by a slider switch that has 1-wire and 2-wire settings. The installation guide for your thermostat will show which one you have. See our article on installation wiring for more info here.
- Confirm the thermostat has been correctly configured for your system. Locate the Installation and User Manuals for your product and confirm the thermostat is correctly configured for your equipment’s system type and stages.
If this is a new installation or the first time you’ve set your thermostat to cooling since it was installed:
Is it time to upgrade your thermostat? Use our thermostat upgrade guide to help you make the right choice for your needs.