Three units previously found to be not heating are still not operational for the same issues. 8297 and 8309 are not operational due to no gas supply pressure to units. 8313 not operational due to failed heat exchanger. 8301 and 8305 are operational in heating mode. Clean out burner and blower compartments. Changed air filters. Clean flame sensors and ignitors. Replaced both the blower and inducer capacitors on both units. Two each of 15uf and 4uf capacitors. Test ran operation from thermostats. Thermostats do not take batteries. Both operational systems are ready for Winter.