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Embassy (Cosmogas) 45WN lock out code 47

biggriz Member Posts: 1
edited March 2021 in THE MAIN WALL
Does anyone have any idea(s) what may be the cause of the L.47 Lockout code on a Embassy / Cosmogas 45WN unit. We've paid right at $900 for parts and labor and still have no hot water. To make matters worse it is a combi so while it is summer here in Alaska, it does get cool at night sometimes and nice to have house heat.

What we've tried:

Called local Alkota dealership and had the tech come out three times for a total right at $???.?? for a collective total of 2 1/2 hours of work. Bought a controller (logic) board (motherboard to me as I am a computer nerd) that the Alkota tech said we needed to buy. All of which provided hot water for less than 3 days and back to cold water.

In addition to changing out the controller board I've also switched out left and right igniter and the flame sensor. All to no avail. Sadly, when I called Alkota five times while sitting in the car in their parking lot since they no longer provide for a retail setting locally, Pam, hung up on me four of the five calls. So, it would appear they only want to take our money and don't want our business anymore since they appear to be incompetent and can't fix the problem.

Reset unit and it keeps going back to L.47 lock out code. Also, boiler never goes above 76° to 80° (before it goes to L.47 lock out) for domestic and I have house heat turned down and on hold so there is no call for house heat. We've been without hot water for 2 weeks now. Hoping someone can see in our clues above what might be the problem and point me in the proper direction so I can either fix the issue myself or hopefully find a competent boiler technician to do the job.

Thanks for any help that you may provide.

John A.
Anchorage, Alaska, USA


  • rick in Alaska
    rick in Alaska Member Posts: 1,457
    According to what i have found, It is a possibility of a blocked flue or air intake, a bad flue temperature sensor, or a control board. Since they already changed the control board and it didn't work, I would say it isn't the control board.
    I would check all around the unit , including looking in the end of each pipe on the outside of the house, and make sure there is nothing in it. Maybe a dead bird or something. There is also a possibility that everything is alright with the intake and exhaust, but the pressure switch is bad.
    Unfortunately, someone would have to check the pressure switch and the flue sensor to see if they are malfunctioning when it is running.
    If it is the flue temperature sensor, it could be the unit is possibly not running right and the flue is running hot. A combustion analysis would tell that.
    Does it lock out every time it runs? That would be a lot easier to diagnose if it happens while someone is sitting there while it did.
    Too far for me to go for a service call, and I am not sure who else to call in Anchorage. I would start with Central Plumbing though, as I know they do service work. If not, check with Ferguson as I believe they sold them.
  • DZoro
    DZoro Member Posts: 1,048
    Has the combustion chamber been thoroughly cleaned? If no obstruction is found in the exhaust and intake, then there is blockage in the combustion chamber, and it needs to be cleaned properly.
    This can be confirmed with a magnahelic connected to the pressure switch, Like Rick said.
  • ratio
    ratio Member Posts: 3,652
    We don't talk dollars here. (You can go back & edit the post via that tractor-tyre looking icon at the top of the post, left of the star, IIRC it comes up if you hover over it.)

    After that, you said that it went away for a few days after the board was swapped out & then came back. You might be looking at a crummy connection to the board. Check the plugs carefully, maybe reseat them a few times. The other thing that comes to mind is a fault somewhere else that causes the main board to fail...

  • kcopp
    kcopp Member Posts: 4,443
    That sensor up top has a clip attached to it. Out of that clip there are two brown wires. That connection is notorious for not being a great connection. See if condensation had fouled it. May need to wiggle it around. If not replace the sensor. Later models they actually placed a vinyl sleeve over the connection to protect it.