I have a RPJ II Comfortmaker natural gas forced air upflow furnace about 14 years old. In the last month the thermostst will cll for heat the induction motor will run but the furnace won't light. A repair man came out and found condensation in the rubber lline that runs from the induction motor to a switch (pressure?) that tells the burner it's OK to fire. Pull the line off blow the water out . Put it back on and it's good till next time? Hours. Days. Sometimes more. Question is Where is the moisture coming from and ow can I stop it? The repair guy said he had no idea could be the flue pipe. Didn't know? Any ideas?