Wolf Range R366 IR Burner exploding on start

[diamondrichlb]

I'm here getting help with a Sub Zero wine cellar leak and thought I might as well revisit our exploding Wolf Range.

The range is about 10 years old. When originally installed it exhibited a problem when we lit the IR burner in the top of the oven. A high percentage of starts resulted in a small explosion with flames coming out of the top of the door while closed. Either the explosion or a burbling type light off where when you open the door and look inside there are flames running across the top of the oven like Saint Elmo's fire. Usually, when the burbling happens you can shut off the oven and the relight is normal with no explosion. Wolf paid for service multiple times and nobody could fix it. One service man said Wolf should replace the oven. The next guy said there was nothing more to do. Somehow I let this fall thru the cracks and the warranty is gone and the oven still explodes from time to time.

In my many looks at this, it seems to have something to do with the #7 801690 Cover, Igniter Shield, Range. The original couldn't take the heat and partially melted requiring me to replace it. When I replaced the shield the burner worked. Then over time the explosions started again. I replaced the shield again and this time there were instructions stating that the shield must be installed with a 3/8" gap between the shield and the ignitor. This means, as far as I can tell, it's pushed on as far as it will go. There is nothing holding it in place other than the tightness of the shield. This, I think, means that over time with the oven door closing and opening the shield moves and the explosions start again. Only a theory.

Can I get input from an expert?

A question: Could an improper gap between the shield and the ignitor cause an explosion like we're having?

Another question: is the ignitor supposed to stay on while the burner is on - like a glow plug? Ours does, although it doesn't have anything to do with exploding gases as the burner is on and working by then.

[Hiroshi]

"booming" ignition is caused by several factors, but the basic problem is gas building up before a sufficient amount of it contacts the hot surface of the igniter. Spacing could definitely be a factor, clogging of orifices meant to direct the initial "puff" of gas at the igniter, or a sluggish igniter that opens the valve too slowly... any one of these or a cumulitive combination could be responsible.

Yes, the igniter should stay on during heat cycles- it is wired through the valve and keeps it open while the burner is on.

[diamondrichlb]

Thanks for the glow plug ignitor answer.

Should I replace the ignitor? I have a new one, but didn't replace it with the shield simply because the new shield seemed to solve the problem and replacing the ignitor didn't seem to be a simple procedure. Then I got another explosion the other day.

Is the problem of the ignitor opening the valve too slow an ignitor problem or a valve problem?

[Hiroshi]

Generally, it is not a valve problem- the igniter is a much more likely suspect. Since you have a tech on the way, watch him to see how he uses the factors mentioned above to "zero-in" on the issue... having the flat igniter handy cannot possibly hurt! For many years, I have simply counted the seconds after the igniter begins to visibly glow... a brand new igniter should open the valve in @ 20 seconds- if that occurs, but the gas is on for a bit before the burner lites, proximity or blockage is is going to be responsible.

[diamondrichlb]

The tech coming out is for the wine cellar not the oven, unfortunately.

How difficult is it to replace the ignitor. Can I do it on top of the range or does it require pulling it out to get to the back?

[Hiroshi]

He will almost certainly take an add-on appliance, especially an igniter job...! 

 

[diamondrichlb]

Ok, I'll try to set it up.

[diamondrichlb]

Ok, set it up to have the tech replace the ignitor. Thanks for the advice.

[LI-NY Tech]

The heat shield on the broil igniter degrades and doesn't direct the gas properly to the igniter causing delayed ignition and a "boom".  Use an OEM broil igniter, it comes with a new shield.

[diamondrichlb]

Thank you for the input. Yes, I have that. I put the shield on and will have the tech install the ignitor when he comes over.

The boom we experienced was right from the get go when the unit was new. It continues to this day over 10 years later.

[diamondrichlb]

Ok, just had the new ignitor installed, turned on the Broil, and BOOM. Flame out the top of the door with the burbling noise inside. Opened the door and saw flames running around the top of the oven. The broiler was not lit, just the flames in the top of the oven.

What to do now?

[diamondrichlb]

Where is the valve that opens when the Broil is selected? I see the ignitor on the schematic, but I don't see a valve for the gas. 

[diamondrichlb]

I should have said I don't see a valve for the broiler. I see a valve down at the bottom for the main oven burner - 27 803254 Valve, Oven Safety Single Hole.

[diamondrichlb]

Oh wait, I see it on the rear view - 7 715109 Valve, Broiler Safety.

[Hiroshi]

So, the tech just slapped the igniter in without troubleshooting the issue??

[diamondrichlb]

I don't know what he could have done to troubleshoot it. He listened to me and I told him what the oven does and what Wolf has done in the past. Is there something else you would have done?

[Hiroshi]

Yes, dismantled the broiler assembly, piece by piece, until I found something to account for what is happening- poked a needle into every orifice, cleared the burner tube with my coil brush, then put it back together and listen for the relation between how long the igniter takes to open the valve, how long I hear the "hiss" of the gas moving, and what kind of ignition I am achieving.

It is best to do this with the oven door open, as natural gas is lighter than air and will not build-up in the oven cavity with the door open. (nobody wants to be knocked in the skull by the door blowing open!)

Am I correct in assuming this unit is Natural Gas? incorrect orifices can make things weird as well.... LP and NG have very different properties.

Edited May 4, 2017 by Hiroshi

[diamondrichlb]

Ok, well all that did not happen. In fact in all the times they tried to make this work over the years that was never done. You should come to Hawaii to service our appliances.

Yes, this is natural gas.

I talked to Wolf customer service and they have turned it over to one of their Customer Advocates. My but Wolf service has changed since we bought this unit. They really seem to want to help now. They are going to look over all the records and perhaps give us a deal to replace this unit with a new unit at a discount. I can see where that's going to cost a lot of $$$ as these babies are not cheap. Otherwise they will see about giving us more service to correct the issue. I don't know what they can do as they have changed every part there is.

[Hiroshi]

Cause, effect, and physics are the foundation of every appliance... I have always slept soundly at night KNOWING there has to be an answer for every symptom... Im sorry my advice didn't get you any closer to a broiler that behaves, but the Hawaii idea has merit, in any case! Good Luck!

[diamondrichlb]

It does seem there is a problem which should be solvable. It's a mechanical instrument. It works or it doesn't. There has to be something or things which if changed will fix the problem. Having said that, there are only so many pieces to this puzzle. If you replace all the pieces and it still doesn't work?

How does natural gas work? Does there have to be a precise pressure and volume for it to work? The gas company says the gas pressure is correct. Does the gas pressure/volume vary per time of day and how many people are using it in a 40 story building? Can that make a difference? We've had this problem at all times of the day. Like today it blew at 10 in the morning. When we use it it's usually 5 PM and it may or may not blow.

I lit it right now at 12:30 and it didn't blow up, but when I opened the door to see if it was working some gas came out of the door and lit off. Not in an explosive way, but the gas was not contained in the burner. When I looked at the burner it was working, but may have just lit when I opened the door as the flames were blue. i waited at least 45 seconds before opening the door to check.

In the past if I smelled gas I would open the door to check and the burner would light when I opened the door. There seems to be an issue with the gas/oxygen mix for this to happen. What do I know? Nothing as I don't know how it works. Seems like it should be simple. The main oven burner works fine and there has never been a problem there. Why is it different?

[diamondrichlb]

Can anyone give me a good online source for Wolf Range parts? I tried the link that comes up on this site and they don't seem to have Wolf parts. You can PM me if that is more appropriate.

[AccApp]

The only source for genuine Sub-Zero and Wolf parts is your regional authorized parts distributor.

[diamondrichlb]

Thank you.

[diamondrichlb]

It looks like we are going to make a deal with Wolf for a new GR366 range. Wolf wants to make sure the gas supply is correct. I seem to remember the gas company coming out years ago and they hooked up an instrument that looks like a curly glass tube with water in it.......help me out here. What is that instrument called.

And what would a plumber look for when testing the gas supply?

[diamondrichlb]

Water column?