Why is there a red light on my Honeywell thermostat?

Thermostat red light flashing or stays on: This means the outdoor unit has shut itself off because of a problem, and it sends a signal to the thermostat, letting you know that there is a problem. When this happens, the indoor unit tends to keep on running because the indoor unit doesn’t know there is a problem.Click to see full answer. Correspondingly, what does the red light mean on a furnace?If your oil furnace isn’t coming on, you may see a red light illuminated on the burner unit. When lit, this red light, also called a lockout light, indicates that a safety mechanism on your furnace has caused a shutdown because it has detected a problem or recognized a fault.Subsequently, question is, how do I reset my Honeywell thermostat? How to Reset a Honeywell Programmable Thermostat Set the thermostat switch to “Off.” Insert a coin into the slot on the battery door to push it open. Remove the batteries. Insert the batteries backward, so that the negative pole lines up with the positive terminal. Remove the batteries and put them back in the correct way, then close the battery door. Also asked, why is my thermostat flashing red? If you see the red flashing light during regular operation, this usually means that the outdoor unit was shut off due to a problem and is currently “locked out” from normal operation. When you see the red flashing light, it is usually in a diagnostic feature to alert the HVAC repair technician to what the problem is.How do I reset my thermostat? Here are the steps you need to take to reset your AC thermostat. Shut Down Your AC at the Thermostat. The first step in resetting your AC thermostat is to turn it off at the AC unit. Find Your Circuit Breaker Box. Reset the Circuit Breaker for Your AC Unit. Wait 30 Seconds. Turn the AC Thermostat Back On.