Magic Chef Oven Repair - Success!

[Russ Chastain]

VICTORY!!!

My oven now lights, and I didn't have to replace any parts. Here's the scoop:

I have a Magic Chef Range in a 1993 Terry by Fleetwood travel trailer. Specs as follows:

Magic Chef
Model BT22RN- 4T
SN 25C245756744
Spec Code 49

We had used the oven successfully in the past, but about a year ago we took a trip and the oven wouldn't light. Just the pilot. So I cooked our bread on my little propane grill along with the meat, which was interesting. The oven pilot would get bigger when we turned the knob to get heat in the oven, but the oven burner would never light.

So I made sure the thermocouple sensor was clean and that it was getting good and hot, which it was. After lighting the pilot and then turning the oven knob on, the pilot would get bigger and heat up the thermocouple sensor until it glowed red, but still the safety valve wouldn't allow gas through to the main burner.

It was looking as if I would have to replace the safety valve, which ain't cheap, and ordering one appears to be a gamble, since every one that I found a picture of that I could order was not exactly like mine, and probably wouldn't have worked.

My safety valve is a Harper Wyman and it looks somewhat like the one pictured here:
http://www.appliance411.com/faq/gas_ran ... tems.shtml
about 1/4 to 1/3 of the way down the page, under the heading "Typical Oven Safety Valves." Not exactly like that one, but pretty close.

I decided to take the valve out and fiddle with it rather than just replacing it. I had nothing to lose but time, and I generally have more time than money anyhow. Plus I figured I should take it with me to a local RV place if I bought a new one, to make sure the new one matched the old. And so I removed it.

I found nothing that looked wrong that I could see from the outside, no blockage in any of the gas hookups or anything, so I decided to remove the six screws holding the back plate onto the aluminum body of the valve. A minute or so with a 1/4" nut driver, and it was apart.

Then I examined the pristine, brand-new-looking interior of the valve, and saw that there was a spring that usually rides against the back plate, pushing a lever towards the front of the valve. The lever pivots in the opposite end of the valve (opposite the side the oven burner connects to), and has a rubber seal that cuts off gas to the oven burner.

I decided that where the thermocouple lead comes into the face of the valve about midway down the length of the lever, the heating of the thermocouple causes some expansion which should move that lever rearward against the spring tension, thereby allowing gas to flow to the oven burner. But that lever wasn't moving. It appeared to be stuck.

So I pulled on it a little, and it suddenly came free. Its rubber face had become stuck to the round seating surface that it seals against, but now that I broke it loose, it moved free as a bird.

A delicious thought entered my brain: "I just fixed this thing."

I pivoted the little rubber thing so it would seal with a new part of its surface that would hopefully not be prone to stick, and put everything back together.

Turned the gas back on at the tanks, lit the stove burners to get gas into the system, lit the oven pilot, turned up the oven knob, saw the pilot grow larger, and held my breath.

I didn't have to wait long... the oven burner lit perfectly in just a short time, like less than a minute.

Checked for leaks around the safety valve, and it appears to be a-okay.

So I saved at least $60 and maybe a lot more. Made me feel pretty dang good!

I put this in a new thread so that hopefully it will be easy to find for folks who have similar problems. I'll link to it from another couple of threads on this subject.

A happy camper,

[mickman073]

Ahhh. As you told me in my thread--PROGRESS--it is a GOOD thing. Good when we conquer the opping motor home gremlins. Congrats Russ.

[Russ Chastain]

Thanks Mick!

[Alpenliter]

Isn't it a great feeling when you put something back together and IT WORKS!

[Russ Chastain]

Yes!! It is pure delight.

[ron buckner]

Warm Fuzzies! Russ, This regulator thing I've been rambling on about is a primary issue with the symptoms you've just described. The "varnishing" you just dealt with indicates you might have a regulator issue. When a reg. goes bad it "surges" (for lack of a better word), and a coating of the substance they put in propane (Mercatim) can begin to build up in the mechanicals of every LP appliance on board. Also, this is real old school, but the simplest way to to check for a bad safety valve in an oven is to take a small burnzomatic torch to to the pilot for about 2 seconds (Just until the thermocuple is red hot), if the burner comes on you have a partially plugged oriface to clean out. If not then the safety is bad and you can do just what you did. Generally, there's enough mercury expansion there to pop ANY safety valve open, you have to be carefull though, it's also a good way to ruin one