RM8551 Fridge Ignites But Keeps Clicking & Shuts Down

[Kingfish]

In the past when I have had problems operating on gas, simply cleaning the orifice and horizontal burner/flue with a bore brush fixed it. I've never tried to clean the vertical flue above the flame. This time, after cleaning, it ignites with a healthy looking flame, but the electronic igniter keeps on clicking and it shuts down after about a minute. Any suggestions would be most welcome!!!

[Vermilye]

Check that the spark igniter is in the flame. Besides providing the spark to light the flame, it also is used to detect that there is a flame. It is possible to have it close enough to light, but not get hot enough to detect the flams, shutting down the gas valve (and keeping the spark going).

[Kingfish]

Originally Posted by Vermilye

Check that the spark igniter is in the flame. Besides providing the spark to light the flame, it also is used to detect that there is a flame. It is possible to have it close enough to light, but not get hot enough to detect the flams, shutting down the gas valve (and keeping the spark going).

That looks like a distinct possibility!! Can the wire probes for the igniter be bent to adjust their position without breaking? Could they possibly need cleaning? Is it possible that part of one broke off since it has a different shape than the other? What else could possibly cause it to suddenly be too distant from the flame?

[Kingfish]

On closer examination I find that the probe closest to the curb side is quite a distance above the flame. Its shape is straight compared to the one on the opposite side. Could part of it have broken off? The one opposite has a hook in it over the flame and is close enough to glow.

[Vermilye]

If the igniter is over the flame & glowing, it is probably in the correct position. Try cleaning it and check for carbon traces (burned streaks on the ceramic support) or insulation failure. Worst case, it may need replacing. It could also be a electronic board problem.

[Kingfish]

Originally Posted by Vermilye

If the igniter is over the flame & glowing, it is probably in the correct position. Try cleaning it and check for carbon traces (burned streaks on the ceramic support) or insulation failure. Worst case, it may need replacing. It could also be a electronic board problem.

Thanks!!
The part in your link is definitely the one considerably outside the flame. The lower one (the one furtherest from the curb) is in the flame but shaped quite different. It has a 90 degree bend at the very tip where it meets the flame. Meanwhile I am going to take them both out, clean'em up, and see what happens.

[Vermilye]

It appears that the RM8551 has a separate electrode used to sense the flame rather than using the same one for both functions. Cleaning both would be good. Also check the wiring from both electrodes. I suspect the shorter straight electrode is the flame sense one but I am not familiar with that model...

[KirkB]

On my RM 8551, the electrode closer to the driver side and vent opening is the igniter. The farthest away (curb side) electrode is the flame detection. The flame detection electrode has a spade connector on the wire, the igniter does not (I assume to avoid arcing). My flame detection electrode has a slight bend (<30 degrees) and sits right in the flame and glows bright orange once the flame is hot. I am working from memory, my trailer is in storage.

I would first try to move or twist the ceramic part of the electrode where it fits in the holder to get the element in the flame, or make sure the spade connector is attached properly.

[Kingfish]

Originally Posted by Vermilye

It appears that the RM8551 has a separate electrode used to sense the flame rather than using the same one for both functions. Cleaning both would be good. Also check the wiring from both electrodes. I suspect the shorter straight electrode is the flame sense one but I am not familiar with that model...

Thanks! Yes it does have separate electrodes. What I don't know is which one is the igniter and which is the flame sensor. I'm going to take them out for a cleaning this weekend and see what happens. One is in the flame and glows. The other is not.

[Kingfish]

Originally Posted by KirkB

The flame detection electrode has a spade connector on the wire, the igniter does not (I assume to avoid arcing).

Thanks!! That should be enough to help me determine which is which.

[Kingfish]

While continuing to troubleshoot I remembered I had not attempted the tried-and-true method of de-pressurizing the propane system and tapping on the valve with a wrench. This fixed it one time before. It worked again this time. All is well!!