Fireplace and furnace clean and tune. Pilot light was out on fireplace. Had a hard time relighting the fireplace. Cleaned ignition assembly and flame sensor. Sparker was not sparking very well and also, it was sparking below the tip of the assembly. Lit pilot and the switch would not turn on gas valve. Jumpers out gas valve and fireplace lit. Weak gas valve. Recommend replacement of gas valve and ignition system. System is operating at this time. Furnace. Cycled system. Checked heat exchanger, found it rusted but no cracks found at this time. Checked gas pressure. Cleaned system. Found it very worn and dirty. Igniter tested normal at this time. Found higher CO in exhaust, but still in normal range. No CO found in airstream. XS air was a bit high, but still in normal range. System is worn, but operating normal at this time. Future failure expected. Job complete. Found micro-particulates at max out of over 50 ppm. This can lead to allergic reactions and breathing issues. Electrostatic