Arrived on site to perform an annual tune up on a propane Miller furnace. After our initial inspection, we provided an estimate to do the tune up. It was accepted. We started by inspecting the igniter. Looked good. While we had the igniter pulled out we inspected the combustion chamber. We found that the refractory had at least two cracks. It will eventually collapse and fall into the heat exchanger. Matt mentioned he wanted to replace the furnace next year but we will be sending an estimate for the refractory just so they are aware of the price if they choose to not replace furnace. We also checked gas pressure, amperage of the inducer and blower motors, and the capacitance of blower capacitor. We found that the blower motor was pulling more amps than it was rated for. We believe it could be due to the fact that the capacitor was out of specification. We tested that capacitor at 9uf and it’s rated for 10uf +-5%. We also checked for CO leaks. None present, system is operating safely