Navien CH180 2 second burn on/off

Discussion in 'Boiler Forum' started by Stephen C, Nov 3, 2013.

  1. Stephen C

    Stephen C New Member

    Messages:
    17
    Location:
    Ontario
    My Navien CH180 ( propane ) combination water heater boiler cycles burner about 2 seconds on and 2 seconds off and repeats on / off 7 - 9 times before it locks on for a long burn cycle . I also had Error 12 - flame out a few times . Error reset by unplugging power and reconnect . Manual says check filter which was fine .I may have had some air from some new baseboard rads I just added . I think air is out now but still have short cycles every time it starts burner. System was new last year and ran fine . I do not use hot water and boiler was off for summer . I do not remember this short cycling but recent remodelling of building may be why I notice noise this year .
    Is this a normal start sequence to prevent thermal shock ? I am concerned about gas pressure or other developing problems and want to know if boiler needs a service check?
    Last edited: Nov 3, 2013
  2. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,535
    Location:
    Houston, TX
    If it uses a CAD cell to check for flame then I would check that.

    Sometimes the lens on the CAD cell can get foggy and needs to be cleaned.


    Good Luck.
  3. zl700

    zl700 DIY Senior Member

    Messages:
    237
    Location:
    Texas
    The Naviens use a flame rod, to sense burner operation.
    Error code 12 means flame loss. This would be due to improper sensing because of a flame rod issue or grounding, or loss of gas supply or improper pressure feeding the unit
    Check the obvious, like tank fill level and confirm the tank is large enough to feed required capacity of all appliances.
    The #800 number for navien is posted all over, consider calling their tech line for assistance.
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,353
    Location:
    New England
    Most (if not all) gas appliances have some means to detect that the main burner actually has started once they open up the gas valve, otherwise, it could be dumping raw fuel into the room and flue and create a major disaster. A typical cycle looks for that main burner to be on for a short period, and if it doesn't detect it for whatever reason, goes into a post purge delay to clear out the raw fuel, then tries again. Depending on the design, it may try that some multiple of times, and if it never sees the main burner come on, it will shut itself down.

    It may be that the sensor is broken, dirty, out of position, or the circuit board it is connected to is defective, or the main burner may not be setup properly, or the main gas valve isn't fully opening, or (maybe you can see the pattern here!) something is preventing it from running properly - could be gas supply, gas valve, burner, sensor, control unit...but, all related to the same thing - the brains don't think the main burner turned on.
  5. Stephen C

    Stephen C New Member

    Messages:
    17
    Location:
    Ontario
    Thanks to everyone for your help . Propane tanks are 60 % at start start and filled recently . All manual shut - offs are on . Flame looks healthy strength blue colour even when only for 2 seconds .You advise that short cycle is not normal which is what I rally needed to Know suspected . E12 only happened twice in 3 weeks so I think regulator or sensor is not fully up to spec but close . When you say ground problem do you mean sensor ground or ground at electrical outlet ?

    Also , install manual says condensate tube must be clear or error will occur . This is not mentioned in error section or in any trouble shouting ? Easy to check and I will do it tomorrow .

    Short cycle is not happening right now . If the problem cleared by It's self , I think the propane regulator might have been sticking from 4 months of no use .
    I will also try factory support and call in service to check over .
    It is very helpful to me to have some ideas from you . I am very isolated . 1.5 hours north of Toronto . I do not know if people in this area are familiar with this technology .People who installed it seam to have disappeared .
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,353
    Location:
    New England
    With anything out of the ordinary, it's tough unless you have a qualified tech...the old school often don't have a clue on how to fix them.
  7. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,535
    Location:
    Houston, TX

    It would be the sensor ground thru its mounting hardware, Not the AC power ground.

    Maybe it took the spiders awhile to move out.
  8. Stephen C

    Stephen C New Member

    Messages:
    17
    Location:
    Ontario
    Thanks again for your input .
    Problem was gone for about a week and now it is back . I think I will clean sensor , Monday I will call factory if problem does not clear . They may know who can fix in my area and they may know about problem .
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,353
    Location:
    New England
    If there's any obstruction in the flue, the thing will also shut itself down after trying to fire. There are numerous safety interlocks. Try reading up on the theory of operation in the user's manual, it may give you a clue and also has some troubleshooting steps as well.
  10. Stephen C

    Stephen C New Member

    Messages:
    17
    Location:
    Ontario
    Cleaned the flame rod today . Dramatic difference . Still a few short cycle starts but often fires up without stopping . Makes sense that shut down for rainy summer allowed some oxidation . It had a bit of rust which I gently cleaned with 400 emery paper . It can be seen thru the combustion inspection window and is mounted with the spark electrodes . Feel relieved as this repeated on off was unnecessary stress to igniter system .
  11. jac04

    jac04 New Member

    Messages:
    21
    Location:
    Connecticut
    I know this is a bit of a late response, but I just registered and have some input on this topic.

    I recently had a Navien CH-180ASME installed and it did the exact same thing - very rapid flame on/off when trying to start. Sometimes it would shut down on Error 12, with a secondary Error 03. Most of the time it would eventually stay firing. Inlet gas pressure checked OK, and gas/air pressure was adjusted to specification.

    It finally turned out to be the propane regulator. The system had a single regulator on it - they called it a "twin" regulator. Navien advised that this twin regulator could not respond fast enough to gas flow requirements when the burner started. A 2-stage regulator system was installed (2 separate regulators), and it was able to start without issue. I had a Navien Tech out at the house a few days ago, and he re-set inlet gas pressure and adjusted gas/air pressure settings, and it seems to be running better than it ever has.

    -Jeff
  12. Stephen C

    Stephen C New Member

    Messages:
    17
    Location:
    Ontario
    Thank You for your reply Jeff
    I cleaned flame rod . Worked for short time . Problem came back . Found original installer who moved to another town and used him for annual service check . He cleaned flame rod and said house wiring might be problem . He said he contacted Navien and they refused to replace flame rod . I put boiler on dedicated circuit and installed new ground on breaker panel . Still have problems . Problem now is it lights up for a few seconds with green light on display goes off and on . I will call in propane supplier about regulator .Thanks for reply Jeff .
  13. MikeG88

    MikeG88 New Member

    Messages:
    3
    Location:
    Connecticut
    I am curious to see how you have progressed with this. I have the same problem, two local plumbers have check the pressure said it was o.k., but I still wonder if I really may need the two separate regulators. I have had the air pressure sensor changed, they swapped my computer board for the high temp version ( I also had to have CPVC exhaust retrofitted), and also enlarged the primary loop, have tried different temperature and supply settings. I no longer get the error 12, but I still see the burner cycle on and off when starting up. Currently I had a new flame rod and am waiting for plumber to return call to install. I really wonder if this is the solution? All told with labor and materials I am out nearly a grand on this problem!
  14. Stephen C

    Stephen C New Member

    Messages:
    17
    Location:
    Ontario
    Here is my update of the problem which is still happening .
    Flame sensor was cleaned twice last year . In December I called Navien . They said flame rod shound have been cleaned with newspaper or a dollar bill . They sent me a new flame rod for me to put in . I waited a week for a warm day to see the problem was back and changed the rod . Worked perfect for almost two whole weeks . E12 and same problem by end of January for about 3 days . February was extremely cold and I pump so much heat in the crawl space to keep pipes from freezing , it hardly had a chance to stop . Mid February I have 3 warm days and I can here it clicking on off 6 times before it lights up . I Unplug it , take the cover off so I can video record the flame and count on off cycles and try to determine if there is a relationship between time off and the struggle to relight . Boiler was unplugged for 15 min . It relights without any problem . I shut off my zone heating pump to hold it off for 15 min without unplugging and it lights perfect every time . I unplug the boiler for 30 seconds , plug in and the problem is back same as last 3 days continuously screwing up for hour after hour each and every time . I unplug the boiler for 15 min. and plugged back in . It lights up perfect for 3 days without a single problem . When your boiler has problems lighting , try unplugging it for 15 min. and then plugging back it to power . I think the microprocessor gets corrupted by a short spike an power line and it does not reinitialize software unless power is off for some period of time . I called Navien today . They told me it sounds like the boiler is short cycling and I need to do a heat calculation on my building or they are not going to help me .I told them I have a problem for 3 days , I unplugged the power for 15 min. and then the problem is gone .
    The boiler has problems getting starter but after the initial short cycles it runs 10 min. That cannot be too short . It should be able to light for domestic hot water for a couple of min and stop when heat is required on a warm day . They told me my well pressure is probably a problem . I have a security camera watching my pressure and it stays on 23psi and never movers . My water main was frozen one day for 12 hours and boiler ran and pressure never moved . They do not have techs in Canada and will not recommend any .
    I think I have to install a new thermostat and timer so if temperature falls critically low it will shut power for 10 min. to allow a reset and then power on constant when boiler stays warm . I will also write to ULC to ask them if they are aware of a possible board problem .
  15. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,535
    Location:
    Houston, TX
    "I think the microprocessor gets corrupted by a short spike an power line and it does not reinitialize software unless power is off for some period of time ."


    That could be it.

    You could use a time delay relay, like used to protect AC units from powering up before head pressure equalizes.

    Or a bigger Capacitor on the CPU power supply may work.


    Good Luck.
  16. Stephen C

    Stephen C New Member

    Messages:
    17
    Location:
    Ontario
    Do not know if corruption is the real cause.
    Last edited: Feb 24, 2014
  17. Stephen C

    Stephen C New Member

    Messages:
    17
    Location:
    Ontario
    I will use a timer you would use to turn house lights on off . It will be be programmed off 10 min . for every 3 hours 24/7 . A thermostat connected in parallel will hold power on always if boiler room is above 55F. Power will only shut down for 10 min. if room is abnormally cold as a backup reset action .
    In my day job , I go around installing caps on solenoids which cause transient spikes that corrupt micros in industrial machines . I will not modify anything in the boiler for legal reasons but I will plug the power cord into a surge suppressor and set up my power cord backup 10 min. power off reset system .
  18. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,535
    Location:
    Houston, TX
    I am not sure if corruption is the cause on your unit.

    I have seen it on a lot of controller electronics that does not have battery backup.

    During Cold weather the power company may switch power sources to meet demand, and that does cause power Glitches.

    What you plan to do would be a easy solution.

    It would be best to use a timer with a ground connection.

    As for spikes from solenoids / relays, If they are DC they should have a Diode across the winding also.


    Good Luck.
  19. MikeG88

    MikeG88 New Member

    Messages:
    3
    Location:
    Connecticut
    My new burner rod was installed and it seemed to run fine while the plumber was here, but later it started acting up again. Maybe it's my imagination but I did notice that if the burner has not run for a longer length of time- it starts up easier? I have the high temp board so it should not be a case of it stopping because the return is too high (they had me have that installed previously for that possible reason), or maybe it starts up with out hesitation because it goes right to high fire because the water has gotten cold? That may play into how some have reported less mis-firing on DHW -which I assume goes to high fire pretty quick?

    I Installed a whole house surge protector before the new board was installed- I had been worried maybe a spike had damage the original board or was causing the problem.
  20. DBC

    DBC New Member

    Messages:
    1
    Location:
    Massachusetts
    This is not a problem with the flame sensor - the sensor is working fine. Which is why cleaning it does not help.

    This is a problem with the gas regulator adjustment.

    If you google the service manual for this boiler you will see that you need to adjust the regulator by turning the screw accessible from the bottom of the unit in the right front corner.

    You need a manometer and some 1/8" tee and plastic tubing to insert the manometer into the boiler to do the adjustment.

    Getting this right will solve all the terrible "jet engine" sounds that people report.

    But it does not always solve the 12e error problem.

    If you still have this problem you need to turn the gas regulator screw another half a turn clockwise - assuming you did the calibration as directed.
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