So thank you guys of the R/HVAC sub and even beyond for your hard work. Details. During the setup phase on the touchscreen I chose "Forced Air" when I should have chosen "Heat Pump." My car has 179000 miles. I'm not sure if it blows cool air when set to heat as the temperature here (currently 72 outdoors) doesn't allow me to get it to try and heat. My A/c then only blew cold air. ... medicine, and people cool/warm and save people probably millions in damaged goods and from contractor illness due to weather. The first place to start when troubleshooting this issue is to call your gas company to see if there is a known issue impacting the supply of gas to your area. The most common issues are: Stuck thermostat. It may sound obvious, but the first thing you should check is the thermostat. Contractor's Assistant: Did you double-check the thermostat's settings? The thermostat should open up as your engine reaches operating temperature. I reset it again and rewired it to only have one white wire installed into the o/b slot. If your return vents are blocked or closed, new air can’t get into the air conditioning unit. Press Menu on the main screen. The instructions depend on which thermostat you have. If the heat pump turns on when you want cool air, but not for heat, this is likely the cause. Incorrect Thermostat Setting Photo by Wesley Tingey on Unsplash. 15. I checked the system monitor data. If you have an oil-fired furnace, you may be out of fuel. Hi Guys, I've just updated all of the thermostats in my new office build. Yes... we are 20 years old. The Furnace Is Blowing Cold Air. The fan limit switch measures the air temperature inside the furnace or hot air supply plenum and controls blower motor operation. Contractor's Assistant: Did you double-check the thermostat's settings? So, I bought a new one (Honeywell Lyric T5). The ventilation fans blow air over the matrix and into the car. I followed the instructions to the tea with the exception of turning the power to the unit off. An air lock prevents the coolant from circulating properly and can cut your heat output. Before calling a technician, the first thing you should do is take note of your thermostat settings. Heat pumps usually produce air that is 85-92°F. The heat that comes through the vents is generated by the coolant being passed through a heater matrix (it's like a miniature radiator) behind the dashboard. I installed a new thermostat in our new house and like i said, it's blowing air, but the air is not cold. Take pictures of the terminal strip on the stat next time. is changing the fan from “auto” to “on”, which causes the fan to blow air when the system isn’t running. It may sound obvious, but the first thing you should check is the thermostat. Other thermostat issues. Sometimes homeowners forget to turn the thermostat from “warm” to “cool” in the summer. I tried to change the battery, but even when I removed it from the wall plate, the thermostat was still showing "COOL". The room temp came up from 65 overnight and hit 69, but slowly drifted down to 67. Nest Thermostat E . Won't be able to test it out until tomorrow, though. This happened last night and this morning. Here’s another possible DIY fix for your heater blowing cold air. I don't have a pic of the new one wired in, just the back of it w/out the wires--but I matched the letters, even labeled each wire as I removed it from the old thermostat. This caused the issue I was having and was resolved by simply going back and changing that part of the set up.