If your HVAC settings appear to be correct, why in the world is your air conditioner blowing hot air? The most basic function of an A/C is to deliver cool comfort, so if you’re feeling a warm blast from the vents instead, something’s definitely amiss. It may be a simple matter you can resolve yourself or it may require diagnosis by a qualified technician. Here are some scenarios that might be at fault if your HVAC settings are blowing hot air instead of cool.
First, double-check all thermostat settings.
Assuming the thermostat’s "On” and set to “Cool” mode, remember to also check the desired temperature setting, too. If that parameter has been bumped upwards, perhaps accidentally, you may simply need to adjust the temperature setting back down into the cool and comfortable range.
Look at the air filter.
A dirty, clogged system air filter may restrict return airflow so much that the system evaporator coil doesn’t extract heat from the air properly. If the filter looks very dirty, change it and see if cooling performance improves.
Compressor breaker tripped.
A central A/C system typically incorporates two circuit breakers. One controls electricity to the indoor components including the blower fan while a separate breaker controls electricity to the outdoor unit including the system compressor. If the compressor breaker has tripped for some reason but the indoor breaker has not, the system blower will still run but circulate only warm air because the compressor isn't functional. Due to high voltage hazards, troubleshooting this scenario is strictly a job for a qualified HVAC field technician only.
Low refrigerant charge.
Refrigerant is the lifeblood of your A/C as it extracts indoor heat and conveys it outdoors where it’s dispersed into the air. A low refrigerant charge will cause the system to blow warm air. An air conditioner doesn’t “use up” refrigerant, therefore, a low level always indicates a leak somewhere. This requires professional leak detection and repair to restore proper refrigerant charge and cooling performance.
If your HVAC settings say "Cool" but the A/C still blows hot, contact the professionals at Hartman Brothers.
Our goal is to help educate our customers in New Haven, Indiana and surrounding Fort Wayne area about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 260-376-2961.