Preformed single system maintenance on a 2025 gas furnace. I tested all electrical and safeties on the inside unit. All tested within manufacturer specifications. I noticed when changing the filter that the return ducts were covered in dust. Dust can cause the system to work harder and run down faster over time. I provided estimates to have the ducts cleaned to help prevent any future issues. I proceeded outside to visually inspect the outside unit. I noticed the unit doesn’t have any type of surge protection on it. By adding surge protection you can help prevent any damage being done to the unit in the event of a lightning storm, black/brown outs and other types of surge. This comes with a $10,000.00 repair allowance and 3 year warranty for the manufacturer on whatever part of the unit it is installed on. Unit was heating upon departure. HVAC ONLY 240V SURGE PROTECTOR INTERMATIC AG3000 OR EQUAL SURGE PROTECTORS PROTECT SYSTEMS FROM SIGNIFICANT POWER FLUCTUATIONS.