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Lockinvair knight failure

Having trouble with knight (400 to700)

1st kept locking out on ignition failure , we took everything apart check out ok. Finally found something in the tube from the gas valve to air intake manifold . Set up gas valve as per instruction. Now unit locks out while running. Has anyone come across this problem. I call lockinvair ,not a lot of help , plus,obits a 15 to 2o minute wait ,for anyone to answer. We asked for a direct line so we could talk to the same tech ,but they would not give it


  • Steve WhitbeckSteve Whitbeck Posts: 669
    edited June 2013
    Model #

    We need the model number of the boiler. WHN or KBN.

    Has this boiler been serviced by You before. Was the combustion set?

    Sounds like it could be running lean, since it now runs check the mixture. What are the readings.
  • Jim PompettiJim Pompetti Posts: 549

    The unit is a KBN o2 is 4.3 co2 around 9 co 90 ppm
  • HI

    The readings look normal. What is the flame signal just before it cuts out?  What were the combustion readings just before it cut out? what is the reason that it cut out. do You have the ability to hook a computer to it. Not being there we need to find out why it is shutting off. Is it possible that the vent is trapping water? Are you sure that the drain line isn't plugged. If the boiler is holding water it will short out the flame rod. If the flame signal suddenly starts to drop just before it cuts out I would think it is holding water. It  Have you checked the heat exchanger for leaks. what color are the flame rods. If they are rust red then it IS a water problem.
  • Jim PompettiJim Pompetti Posts: 549

    Flame signal running is 12.2 , sometimes it runs for days . I'm never there when it fails.
  • Jim PompettiJim Pompetti Posts: 549

    May have found the problem , Low fire #'s were off . Since the access was taped off , and said do not remove . We never access it. Finger crossed
  • Knight

    offset screw has to be adjusted. Runs great at mid or high fire but on low fire it leans out and cuts off. Call the factory rep and find out how to adjust the offset screw. They are VERY touchy.
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