If your furnace begins making unusual noises like banging, whistling, or grinding, or if there are strange smells like burning or mustiness, it's important to turn off the unit immediately and contact a professional. These could be signs of mechanical issues, blockages, or electrical faults that might require urgent repairs.

You can test the efficiency of your HVAC system by monitoring your energy bills and noting any significant increases in usage, which might indicate inefficiency. Another method is to check the age of your system; if it's older than 10-15 years, it might be less efficient than modern systems. Additionally, professional HVAC services can conduct detailed energy audits.

First, check if the thermostat on your water heater is set to an adequate temperature, which is typically around 120 degrees Fahrenheit. If it’s properly set, inspect the unit for any signs of leaks or corrosion. If these basic checks don’t resolve the issue, it might be time to call a professional to check for more complex problems like heating element failures or sediment buildup.

Regularly replace your HVAC filters every few months to prevent dust and debris from accumulating in your ductwork. Consider scheduling professional duct cleaning every few years or more frequently if you notice dust buildup, mold smells, or if your home has undergone major renovations. Ensuring that vents and registers are not blocked by furniture or curtains also helps maintain good airflow.