Heating & Cooling Combined Unit: Why is my furnace not blowing hot enough?
Check the thermostat settings. If the furnace fan is set to run constantly but the temperature setting isn’t set high enough to call for enough heat, adjust the thermostat. If the thermostat isn’t working properly, replace it.
If the thermostat is set properly and working as it should, check the air furnace air filter. A dirty filter will block air flow through the heat exchanger and air vents in your home. Replace the air filter if it’s dirty.
If these tips don’t help, then a problem with the furnace burners or the blower fan could be causing the heating problems. Have a service technician examine and repair the furnace if you’re not able to restore proper heating.
THESE REPAIRS MAY HELP SOLVE YOUR HEATING & COOLING COMBINED UNIT PROBLEM
Replace the HVAC system thermostat
The thermostat controls the heating and cooling system in your home. The thermostat senses the temperature inside your home and cycles the system on and off to maintain the set temperature. When your HVAC system control thermostat quits working, replace the thermostat.
Hvac system thermostat
How to replace a heating and air conditioning system thermostat
If the buttons on your HVAC system control thermostat don't work or if the display panel doesn't light up, the thermostat may need to be replaced. This DIY repair guide explains how to replace a thermostat in less than 30 minutes.
Replace the furnace air filter
Replacing the furnace air filter regularly to keep your furnace heating efficiently.
A dirty air filter inhibits air flow through the furnace heat exchanger and your home’s air vents. If your furnace isn’t heating as it should, check the air filter and replace it if it’s dirty.
To replace the air filter, shut off the furnace and allow the blower fan to stop if it’s running. Open the filter access door and pull the old air filter out. Position the new air filter according to the air flow arrow on the side of the filter and slide the new air filter into the filter housing. Close the filter access door. Turn the furnace back on to restore heating.
Furnace air filter
Most common symptoms to help you fix your heating & cooling combined units
Choose a symptom to see related heating and air conditioning system repairs.
Thermostat problem, clogged air filter, burner failure…
Dirty air filter, clogged condenser coils, low refrigerant charge, faulty compressor…
Thermostat problems, bad compressor/condenser fan capacitor, lack of refrigerant, failed compressor…
Main causes: errant thermostat settings, lack of electrical power, clogged drain line, wiring failure, control failure.…
Main causes: Errant thermostat settings, lack of power, bad interlock switches, lack of exhaust ventilation, wiring fail…
Dirty flame sensor, failed flame sensor, damaged burner, bad high limit switch…
Most common repair guides to help fix your heating & cooling combined units
These step-by-step repair guides will help you safely fix what’s broken on your HVAC system.
How to unclog the air conditioner drain line
The condensate drain line for your central air conditioner can clog with mold and mildew. Water will back up and start d…
How to replace the furnace flame sensor
The flame sensor detects when furnace burner flames are lit. You may need to replace the flame sensor if flames only sta…
How to replace a heating and air conditioning system thermostat
The control thermostat for your HVAC system can stop working. This repair guide shows how to replace it.…
Effective articles & videos to help repair your heating & cooling combined units
Use the advice and tips in these articles and videos to get the most out of your HVAC system.
Learn how to maintain your central air conditioner to keep it running smoothly all summer long.…
Get tips to help keep your central AC running all summer long…
Get answers to frequently asked questions about Sears and Sears PartsDirect.…