2. Ducted Heater blowing cold air | No longer blowing warm air
a. Gas supply interruption. Check the heater’s gas valve turned ON. If you have more than one gas appliance, find out if they are working.
b. The pilot light is off. If your heater was made before 1999, it probably still has a pilot light. There are instructions on a unit for how to relight it. However, you are dealing with gas and fire, so don’t do anything you’re not 100% comfortable with.
c. Overheat lockout due to a Restricted Air Flow. Listen for a whistle. If the heater can’t get enough air through the filter, it pulls air through any opening it can. A whistling sound is an indication of a problem. Check, clean or replace return air filter. Ensure minimum 7-10 outlets/vents are open, it's required for an adequate airflow.
d. Main control board in a safety lockout or malfunctioning. Switch ON/OFF power to the heater to reset Main control board.
If the unit is still blowing only cold air after trouble shooting all these steps, we are ready to help. Contact REPAIR Heating & Cooling and our Technicians will identify and solve the problem for you.