We got to the job site we tried turning on the furnace but it seems like the igniter was not turning on Something was presenting the pressure switch from closing. After troubleshooting a pressure switch we found out that it was working properly. After troubleshooting all the controls and make sure everything was working properly. I focused on flue pipe and found out it was all rusted and the chimney was completely clogged. That was the problem that was preventing the pressure switch from closing . If the pressure switch does not close The igniter will not turn on and let the main gas valve will not open and let in the gas to the main burners to ignite . After running new flue pipe for both of the furnaces We installed a Tee flue pipe fitting that's what connects both of the Furnace to the existing chimney lining kit. Now we start up the furnaces.Both systems are turning on properly venting beautifully and running efficiently. Another job well done by The Price is Right Heating and Air Conditioning HVAC company.