Preformed heating maintenance on a single system gas furnace zoned. I tested all electrical components inside the furnace and all tested within manufacturer specifications. Temperature being supplied to the home was at 107 degrees and 80 return. I changed the filter for the client. Aprilaire 210. Checked for cleanliness of the unit and duct work. All is clean. I noticed the unit did not have surge protection on it. I provided estimates for adding 2 surge proctors one for the inside unit and one for the outside unit. Unit was cooling upon departure
