Suburban Oven - Intermittent Flame

[davescounry]

Hello all -

Pretty new to the forum, and got great advice in another thread, so figured I would try again.

I've been running through systems on my new Heartland Trail Runner, and I think I have everything worked out except for the oven. This is a Suburban oven with the 3 burner cook top.

My situation is this - I can light the pilot OK, but then when I turn the knob to desired temperature, I experience a delay. Then the burner will try and light, then light all the way for about 3 to 4 seconds, then shut down. After about a 5 second pause, it repeats the cycle. The cook top burners work fine.

I had actually called me dealer today since initially I wasn't waiting even long enough for that first surge. They explained to me the thermocoupler wasn't getting hot enough and to give it a few seconds. So, I did and tonight I went to test and that is when I experienced this intermittent surging. I tried this a couple of times and the behavior was consistent. After about a minute, the smell of gas is pretty strong, so obviously I have to shut it down.

Any ideas? I may toy with re-lighting the pilot and then waiting a half hour or more before turning on the oven. Of all the things to go wrong, this is about the lowest priority, but I paid for a working oven and I'd like to have it. Plus, we are taking it out this week for the first time and my daughter really wants some triple chunk brownies.

 

[danemayer]

The general sequence of events is:

1. Press and hold the oven dial and use a flame to light the pilot
2. Continue holding the dial in to allow the pilot flame to heat up the thermocouple
3. With the oven dial set to a cook temp, if the thermocouple is up to temperature, power goes from thermocouple to the gas valve, opening the valve so propane can flow.
4. The burner lights.
5. You release the dial.
6. The gas valve should stay open if the thermocouple is operating correctly.

From your description, the burner lights, but when you release the oven dial, it goes out. Make sure the thermocouple is in the path of the pilot flame. Also, the pilot flame has to be large enough to envelop the thermocouple tip.

 

[davescounry]

Dan -

Close. I will run through it again after I tuck my kids in to bed, but here is a closer sequence.

1. Light pilot, hold for 10 - 20 seconds to stay light.
2. Turn dial to desired temp, let go.
3. Nothing happens for about 10 seconds, then burner attempts to light.
4. Cycles off, pause for about 10 seconds, then burner attempts to re-light. Burner lights for 3 to 4 seconds, then shuts off
5. Repeat of 3 and 4.

Note, I am not holding in the dial after I turn it to desired temp. I just turn it and let off. Is this an error? Should I hold it in until the burner lights?

I will run through this again and pay closer attention to the pilot to thermocoupler position. Every time I run through this, I end up with gas odor, so tend to shut down for a decent length of time to air out.

 

[danemayer]

Once the pilot is lit and staying lit, I believe rotating the dial to the desired temp should cause the burner to ignite immediately. The 10 second delay sounds like you have inadequate propane flowing through the burner. After 10 seconds there's enough to ignite the burner, but not enough to keep the burner going. Then after another delay, there's enough propane to ignite, but again, not enough to keep going.

I think you need to investigate the propane flow. Start at the tanks. Close the valves, wait 15 seconds, re-open verrrry slowly. There's an overflow protection device that activates if you open the valve quickly.

If that doesn't help, make sure both tanks are re-opened.

If that doesn't help, make sure your furnace is working ok. If it is, I'd start looking for a pinched propane hose or other impediment to propane flow. If you can get a good flame from all 3 stove top burners at the same time, the problem may be inside the oven.

 

[davescounry]

Well, ran through the sequence again and it was interesting.

I lit the pilot per directions, and went ahead and waited about 15 mins before attempting to turn on the oven. That didn't make a difference.

Observationally, I noticed two things, and tried to take pics. First is that the pilot barely seems to touch the thermocoupler. Second is that when the intermittent surge of flame happens, it isn't coming down the burner as I would have expected. Rather, it is coming from the back of the burner in one big surge of flame. Both are hard to see in these pics, but thought I would try and post them anyways. The one showing the pilot, the flash kind of obscures the top of the flame and the other is just dark, but kind of shows what is happening.

I am going to email these pics to the dealer and call them tomorrow. Thanks for the guidance. I will post back with what they tell me. We might have to make our brownies at home on this trip.