Heating & cooling repair guides

Checking settings, cleaning filters and thawing a frozen coil are safe DIY steps. Cleaning the outdoor unit is fine only with power off at the disconnect. Refrigerant, capacitors, compressors and wiring are for a licensed technician.

Checking the thermostat, filter, power switch, breaker and condensate line is safe for homeowners. Gas valves, burners, igniters, heat exchangers and wiring are for a licensed technician, and any gas smell means leave the home and call for help.

Yes. Most thermostats run on low voltage and are safe to troubleshoot, as long as you switch off power to the heating and cooling system at the breaker before touching wires. Line-voltage (mains) thermostats for electric baseboard heaters are different and should be handled by an electrician.

Yes, changing an HVAC filter is one of the safest and most useful home maintenance jobs. Just turn the system off first and make sure any access panel goes back on properly.