I received a call from a customer who needed a furnace estimate. I went to the customer's home and took measurements and photos of the existing furnace. I then used my knowledge of heating systems to provide the customer with an estimate for a new furnace. I explained the different types of furnaces available and the benefits of each. The customer decided to go with a high-efficiency furnace and I provided them with a quote for the installation. I also provided them with a list of recommended maintenance items to keep their furnace running efficiently.