Shipmate stove repair: oven pilot light sensor

[Trekka]

I have an old Shipmate stove with 3 burners and an oven. Has been a champ all these years! But recently I cannot get the oven to light. The pilot light will burn while I hold down the button that feeds it. But no matter how long it is held down and the pilot is lit, as soon as I release the button the pilot flame goes out. In the past a count of 15-20 before release was sufficient for it to continue.

I sanded what I first thought was the thermocouple (pilot sensor), and the pilot flame burned bright from the tip. But when I let up the button, even after 30-60 seconds, it goes out right away

Based on advice I was able to take apart more of the pilot/thermo assembly and now believe that the thermocouple is bad, not just a matter of needing cleaning. In this oven the thermocouple attaches about an inch or two behind the pilot light into a block that holds the pilot tube. In addition to holding down the button to allow the pilot to burn, I held a grill lighter against the asssmbly the thermocouple screws into. Despite a constant flame right on that for over a half minute, the pilot again went out after I released the button. I figure if it doesn't stay lit after directly heating the coupling that much, then the thermocouple has to be bad?



Does anyone have advice on how to get access to where the thermocouple attaches behind the right side oven wall? As seen in the picture below, I tried to remove that interior wall, but was unable to do any more than pull the botton back corner out a bit.



I have removed all the visible screws and mounts that would prevent the side coming out. But it is not inclined to move. I can feel insulation behind the wall. Before I apply more force I am hoping for some insight from someone experienced with this.

[GordMay]

Does this help?
➥ http://www.suremarine.com/stove-repair.htm

[capngeo]

That is called a generator. Heat sends a millivolt "signal" to the valve allowing it to remain open. The "light" position on the valve holds it open manually. I'll bet you can match up replacement parts at any appliance repair store that has gas parts. To the best of my knowledge, there are no "special marine rated" generators

[Play Actor]

I have the same stove, and I've had the problem you describe a few times over the last 25 years. You've cleaned the pilot burner and thermocouple in the oven. The next problem point is where the fitting from the thermocouple - not the gas line to the pilot - screws into the gas valve.

Unscrew that connection and clean everything thoroughly, including the threads and the connector surfaces inside, especially the shoulder of the threaded ferrule that bears on the back of the button on the end of the thermocouple lead and the threads on the ferrule. Put it back together and make sure it doesn't leak. If sealant is necessary, use sparingly so that you don't insulate it electrically. The thermocouple should produce around 18 milivolts, measured at the gas valve connector while it's open if you want to test by heating the oven end of the thermocouple before reassembly, but you need a really good voltmeter to test it. This has fixed mine a number of times over the years. Thermocouples rarely fail unless damaged physically, but because of the very low voltage produced, the slightest corrosion at the connections will disable the system.

It's also critical that the pilot flame is correctly adjusted so that there is just the slightest yellow edge around the blue flame. Too much or too little yellow, and the pilot will not heat the thermocouple suffciently. There's an adjustment screw, often under a cap, on the gas valve.

Hope this fixes it. If not, thermocouples are easy to come by, although an exact replacement for the integrated pilot burner / thermocouple that's used on our stoves might be hard to find.