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UPC TG9S Furnace

FitterFreds Member Posts: 15
Upc/York/Johnson furnance locked out on pressure switch code. 6 blinks.Reset unit will run 5-10 minutes then start to pulse the burner and shut down. Condensate is clean and flows, venting is clear, gas pressure is 10" incoming, 3.5" manifold. Collector box pressure when running -0.80", inducer -1.5". Inducer pressure will bounce. Am I loading up the secondary with condensate? There are signs that the collector box is leaking. Hair line cracks @ the condensate trap. Replaced pressure switch, control board. NEED SOME HELP ASAP!


  • Tim McElwain
    Tim McElwain Member Posts: 4,480
    How old is this system and has

    it been serviced and has the secondary heat exchanger been cleaned?
  • FitterFreds
    FitterFreds Member Posts: 15
    Start up date...

    Start up date 9/12/10. No regular service done by me. I have not cleaned the 2ndary nor understand that process.
  • Tim McElwain
    Tim McElwain Member Posts: 4,480
    The un it is now over three years old.

    These units need serviced once a year. The condensate system needs to be flushed along with the secondary heat exchanger. A combustion analysis should also be done. I would suggest getting a service technician to take a look at your system.
  • FitterFreds
    FitterFreds Member Posts: 15
    I am a tech

    I am a service tech. Just not familiar with this product. What do you flush the secondary with? Just water, Do you remove the collector box and flush each tube? Do you remove the turbulators.(sp) There are 4 of these units @ this facility and not having issues with the others. Wind Chills will be -60 deg. On Monday and won't have a lot of time for this unit. Want to take care of it soon.
  • unclejohn
    unclejohn Member Posts: 1,749

    Your vent system. Will it run with the air in pipe removed. Will it run with the vent pipe removed. If it runs with one or the other pipe removed check that pipe for crude in the pipe., Are you recirculating vent gas into you air in pipe?. Some of those furnaces had a restricter plate on the outlet of the secondary if it's deteriorated you may be recycling combustion gas.
  • JStar
    JStar Member Posts: 2,752

    Is this the dreaded clear plastic secondary cover? UGH! I've replaced dozens of those because of cracks. Sometimes, the same one 3 times.

    As said, make 100% sure that both combustion pipes are clear. Make sure the gasket behind the inducer is in tact. Also verify that the inducer is actually working and moving enough air. Seen a few broken impellers in those inducer housings.

    Check the pressure tubing and barbed fitting port.
  • FitterFreds
    FitterFreds Member Posts: 15

    Yes clear plastic collector box. They have come out with a new style. Like I stated in my original post venting is clear. I've actually went as far as to remove all venting from the unit. Still has the problem. Going to tear into the heat exchanger.