Norcold refrigerator "NO FL" code, propane burns fine

[ichudov]

I have a norcold refrigerator in my Monaco Windsor motorhome.

1) It works fine on AC
2) When run on propane, it gives a "NO FL" error
3) When performing diagnostics, I was watching the flame as someone else turned it on from inside. The flame started and burned just fine with nice mid-sized blue flame. The thermocouple above the flame was glowing red hot.
4) However, despite a good flame, the arc lighting attempt never stopped, and after a minute the fridge shut down with NO FL.
5) I blew all crud from there with a compressor. A lot of **** came out.
6) This cleaning did NOT help and the fridge still would not run on LP.

Any idea what else I can do. I would prefer a DIY fix as I need to know how to fix this RV while on the go. Thanks

Thanks

[Edd505]

Norcold Manual error codes

https://www.manualslib.com/manual/327885/Norcold-1210.html?page=22

Mine just back from RV repair - bad high temp cut off

[ichudov]

Alright, here's a very happy followup!!!

I purchased a replacement board on Amazon. Took me a while to get my act together to switch it out. Finally I switched it and made sure that I reconnected all leads correctly.

I am DELIGHTED to report that now the flame burns great and the fridge is working very well!!! No problem!!!

It was the board!

[dougrainer]

ichudov wrote:

Jim@HiTek wrote:

ichudov wrote:
Thanks guys for guiding me. I have replaced the spark wire yesterday. The sparks work GREAT and the flame starts every time.

However, despite that, flame is still NOT detected.

The "tower" on top of the control board, from where the spark electrode terminal comes out, is NOT loose.

I feel that I am making progress, eliminating possibilities at acceptable cost, but still no final resolution.

In that case, then you probably need to follow Doug Rainers instructions above. If you can solder and have the equipment that is...

Good luck!

You don't open it up. You remove the main board and look behind the board and re-solder the Piezo pins that are soldered. Doug
Thanks! I will try to see how I can open up that Piezo tower. I can solder no problem.

[ichudov]

Jim@HiTek wrote:

ichudov wrote:
Thanks guys for guiding me. I have replaced the spark wire yesterday. The sparks work GREAT and the flame starts every time.

However, despite that, flame is still NOT detected.

The "tower" on top of the control board, from where the spark electrode terminal comes out, is NOT loose.

I feel that I am making progress, eliminating possibilities at acceptable cost, but still no final resolution.

In that case, then you probably need to follow Doug Rainers instructions above. If you can solder and have the equipment that is...

Good luck!

Thanks! I will try to see how I can open up that Piezo tower. I can solder no problem.

[hostage]

If it was me I would have just replaced the whole board in the first place there only 200$ or less and its 14 years old if its original

[Jim]

ichudov wrote:
Thanks guys for guiding me. I have replaced the spark wire yesterday. The sparks work GREAT and the flame starts every time.

However, despite that, flame is still NOT detected.

The "tower" on top of the control board, from where the spark electrode terminal comes out, is NOT loose.

I feel that I am making progress, eliminating possibilities at acceptable cost, but still no final resolution.

In that case, then you probably need to follow Doug Rainers instructions above. If you can solder and have the equipment that is...

Good luck!

[ichudov]

Thanks guys for guiding me. I have replaced the spark wire yesterday. The sparks work GREAT and the flame starts every time.

However, despite that, flame is still NOT detected.

The "tower" on top of the control board, from where the spark electrode terminal comes out, is NOT loose.

I feel that I am making progress, eliminating possibilities at acceptable cost, but still no final resolution.

[nicksmarto]

Agreeing with Jim@HiTek, I just had the same issue on my Norcold N841. Detected the resistance on the electrode to be about 1.5? but quickly dropped to ~0.1? as the multimeter applied testing voltage.

Cleaned and now that number stayed ~0.5?. Would guess that the actual resistances vary a bit based on conditions, but the moral of the story is that I fixed it by removing and cleaning the electrode tip and all of the connectors of the spark/sense electrode. Happy to avoid replacing the power board.

[dougrainer]

ichudov wrote:

dougrainer wrote:
The Spark Electrode sense the flame and also sends the spark. IF the spark sparks and lights, then the Piezo tower on the board(where the spark electrode wire spade connects to) is defective OR (most likely) the solders for that Piezo Tower have ben broken loose.
Doug

Doug, sorry, I lost you here, if the spark sparks and lights, then the piezo tower is NOT defective, right?

The flame lights up easily and burns well (it looks like it burns ok)

NO, It does not take much for the Piezo to send the hi voltage spark. A loose connection can do that. BUT, the return flame sense voltage cannot overcome a loose solder connection. I should have worded my post better. The FIRST thing you do is replace the Spark/Electrode assbly. Then check and do the solder if needed. It is RARE for a control board to be the fault from No FL. You can usually tell if the Piezo Tower is loose on the board. Remove the black cover and try to wiggle the Piezo tower. IF it moves slightly, the solders are loose. Doug

[ichudov]

dougrainer wrote:
The Spark Electrode sense the flame and also sends the spark. IF the spark sparks and lights, then the Piezo tower on the board(where the spark electrode wire spade connects to) is defective OR (most likely) the solders for that Piezo Tower have ben broken loose.
Doug

Doug, sorry, I lost you here, if the spark sparks and lights, then the piezo tower is NOT defective, right?

The flame lights up easily and burns well (it looks like it burns ok)

[dougrainer]

The Spark Electrode sense the flame and also sends the spark. IF the spark sparks and lights, then the Piezo tower on the board(where the spark electrode wire spade connects to) is defective OR (most likely) the solders for that Piezo Tower have ben broken loose. The most common thing to do this is NOT using a back up tool when removing the the Spark plug wire from the Piezo tower on the control board. What you do is remove the Control board and where the Piezo tower is soldered on the back side of the board, you re-solder those points. IF that does NOT fix it, I would replace the Spark Electrode. It takes minimal flow to SPARK the ignition. but requires perfect return to the board from the electrode to sense the flame. I would replace the Spark Electrode/wire FIRST, then do the solder if needed. IF the Spark Electrode and the solder of the Piezo tower fails to fix, then you have to replace the board. If there is a hairline crack in the White ceramic of the spark plug, the return flame sense signal will not make it. Doug

[Jim]

The terminal at the PCB for the ignitor should be squeezed a little with a pair of needle nosed pliers to make a really tight connection.

The flame is sensed by the ignitor itself. The flame causes a low resistance path from ground (the metal tube where the gas exits as a flame) to the ignitor. The circuitry is designed to send a high voltage pulse to the ignitor, then switches to a low current sensing circuit. When the spark causes a flame, the flame lowers the resistance of the ignitor just enough that a high sensitivity circuit can measure those few hundred microamps of current flowing so it keeps the propane valve ON. Otherwise, it turns it off, resets everything, then tries again.

I believe it gives it 3-5 tries, with a wait period between tries, before it gives up and throws a NO FL code. Your book should tell you.

[ichudov]

Thanks to all. This is a followup.

I have spent some time looking at this today.

As I said, the propane fire lights up nicely, but attempt to ignite the fire continue and after a minute, the fridge shuts down with NO FL error.

I have cleaned, and applied copper based grease to, the terminal for the ignitor.

It did NOT help.

Additionally, I took OUT the igniter head and cleaned it with sandpaper. It did have some crud on it.

That ALSO did NOT help.

Any idea what I can do further to fix it? How is flame sensed exactly?

Thanks!

P.S. I ordered a replacement ignitor since they are inexpensive and easy to replace. I will change it and report the results soon.

[Chris_Bryant]

The current runs through the electrode and ground. Often, if the board is bad it is because the coil the electrode plugs in to has broken away from the board.