Wolf DF 30-4 Oven Cold.

[etherhuffer]

No heat on broil, convect, bake settings. No error codes. Reset breaker for30 secs, no change. Ohm on bake element, 44 one side, 50 other. Live test to bake elements, only 30v each. 
Display panel dims, but works. 
I think it lost its brain. Control head removal and check next? Heads are 400 smackers new, 200 rehabbed. Thoughts?

[ECtoFix]

Control head and smackers?    What is this strange language that you speak?

If you're only reading 30vac across each element, then you're dropping a significant amount of voltage somewhere.  I recommend testing from the outlet first, then work your way to the control board and to the elements.  Somewhere there's a crusty, burnt connection which is dropping that voltage.  It might be found visually, but then it might not.  Your volt meter will reveal it.

Your problem could be...

• a faulty wire connection to wall outlet.
• a bad power cord cap (plug).
• a bad connection from the cord to the input terminal block.
• a failing relay on the control board.
• or other possibilities.

Since I'm not there to do proper tests, it's impossible for me to provide any further guidance based upon what you posted.

[etherhuffer]

2 hours ago, ECtoFix said:

Control head and smackers?    What is this strange language that you speak?

If you're only reading 30vac across each element, then you're dropping a significant amount of voltage somewhere.  I recommend testing from the outlet first, then work your way to the control board and to the elements.  Somewhere there's a crusty, burnt connection which is dropping that voltage.  It might be found visually, but then it might not.  Your volt meter will reveal it.

Your problem could be...

• a faulty wire connection to wall outlet.
• a bad power cord cap (plug).
• a bad connection from the cord to the input terminal block.
• a failing relay on the control board.
• or other possibilities.

Since I'm not there to do proper tests, it's impossible for me to provide any further guidance based upon what you posted.

Thank you, after running out of time and brain power, it occurred to me as well that voltage loss check starts at the wall outlet. Afraid to find what is behind this thing. Might be enough to provide script for a horror movie! 

[etherhuffer]

Power to outlet, both legs read 120.  Power at connectors, 120 each leg, so cord is good. 

Found more info on electronics. ECH is the control panel face and board, then a relay board, then another control board. Going to pull face off the front and look at the relay board. Since all elements are cold and I have main power, may be a bad main relay or relay solder point.  Any other suggestions? 

[ECtoFix]

12 hours ago, etherhuffer said:

Power to outlet, both legs read 120.  Power at connectors, 120 each leg, so cord is good.

Given that you're telling me 120v here and there, I'm calling a "foul".

You're making a common mistake of referencing neutral (or ground) for your voltage readings in a 240v circuit.  Don't do that.  The only things in that range operating from NEUTRAL are the gas rangetop controls, the convection fans, the door lock motor for self-cleaning, the transformer for the halogen lights...and the relay board which CONTROLS the oven elements.  NEUTRAL (or ground) has absolutely no bearing on the actual 240v-driven power (which you're lacking) that is supplied to oven's heating elements. 

So the actual elements are pwered from 240v. THAT voltage can only be read from the wires fed from L1 to L2 (120v from L1 + 120v from L2 = 240v).

A good visual inspection might identify your problem.  Scrutinize ALL of your wire connections and the integrity of the bi-metal thermal cutout before wagging a suspicious finger at the relay board.  If you get down to that, you should do some strategic L1 to L2 voltage into and out of it tests by using the diagrams in the service manual.

To see those diagrams, do a search online for a "wolf DF304 service manual".  The diagrams are on pages 7-2 to 7-4 (CONTEXT-ually) - or 82 to 84 (PDF-ly).

 

 

[ECtoFix]

1 minute ago, ECtoFix said:

If you get down to that, you should do some strategic L1 to L2 voltage READINGS into and out of it using the wiring/schematic diagrams in the service manual.

I hate that I can't edit my relies here in this forum.

[ECtoFix]

Just now, ECtoFix said:

relies

REPLIES!  Dangit!

[Craig Knight]

Are you able to perform any current readings?

[Craig Knight]

I just located a technical manual online. It is interesting at the amount of technical data supplied in it.

Which elements were you checking? The 18” or 30/36”?
 

[etherhuffer]

16 hours ago, ECtoFix said:

Given that you're telling me 120v here and there, I'm calling a "foul".

You're making a common mistake of referencing neutral (or ground) for your voltage readings in a 240v circuit.  Don't do that.  The only things in that range operating from NEUTRAL are the gas rangetop controls, the convection fans, the door lock motor for self-cleaning, the transformer for the halogen lights...and the relay board which CONTROLS the oven elements.  NEUTRAL (or ground) has absolutely no bearing on the actual 240v-driven power (which you're lacking) that is supplied to oven's heating elements. 

So the actual elements are pwered from 240v. THAT voltage can only be read from the wires fed from L1 to L2 (120v from L1 + 120v from L2 = 240v).

A good visual inspection might identify your problem.  Scrutinize ALL of your wire connections and the integrity of the bi-metal thermal cutout before wagging a suspicious finger at the relay board.  If you get down to that, you should do some strategic L1 to L2 voltage into and out of it tests by using the diagrams in the service manual.

To see those diagrams, do a search online for a "wolf DF304 service manual".  The diagrams are on pages 7-2 to 7-4 (CONTEXT-ually) - or 82 to 84 (PDF-ly).

 

 

Yes, got that advice from another source as well. 

Drilled down in the manual and found the diagnostic section, which my addled brain bypassed (been busy, blown water tank with flood, dead furnace, dead stereo all in the last month and I am stoooopid tired.)  Ran through checking error codes. None. Ran through test mode, no 'call for heat' in any setting I check. Ouch. 

[etherhuffer]

11 hours ago, Craig Knight said:

I just located a technical manual online. It is interesting at the amount of technical data supplied in it.

Which elements were you checking? The 18” or 30/36”?
 

I found the manual as well. And the tech page for ohm readings on elements. Everything ohm'd out within spec. The bake element is actually two elements that lie in a tray. Both good. Convection elements good. Broiler good. Bad part? Good grief, filth. lots of filth. Had not pulled the unit in a few years. Dusted up control boards, nasty spills on the sides. You know the bad part of being semi-competent with this stuff? You get the dirty part of the job with the fun part! hahahahaha!

[ECtoFix]

7 hours ago, etherhuffer said:

You get the dirty part of the job with the fun part! hahahahaha!

Yes. Fun.

I  work solely on repairing commercial stuff (no residential) and this evening I relished in finding myself addressing the failings of a big ole Hobart "flight" dish machine (model FT900) at a huge hotel. 

Amongst the muck and funk I was surrounded by, an audience of cockroaches observing my "troubleshooting & repair" performance offered little to NO feedback (no laughs, advice...or applause for my successful repair).  INSTEAD, their congregation of little-uns were more concerned with seeking out every nook and cranny as any refuge they could find.  With my being new there, they appreciated the new overhead I provided by scampering underneath my hand-tools, my multimeter, my tool bag...and even ME as I was perched upon several dish racks above that (potentially) vomit-inducing Terra-cota tiled floor. 

YES. I thoroughly enjoyed all of the good and the bad (because I love my job).

****************************************************************************

Sounds like you have the tools and reference material you need to repair your range.  After my looking at the service manual, I'll admit that it appears to be quite a complex appliance on the controls side.  I hope what you find ends up being something simple and you get it figured out. 

[AccApp]

Did you find a popped joint under a relay on the relay board? I had a similar problem on my DF48 and I was able to clean it and resolder it and it has been working for years now.

[Rhubarb Tau]

Sounds like a bad DBL relay or open thermal limit, measurements would confirm.

The thermal limit is on the back, but easy-ish to reach by removing the convection fan. As I recall it's at about the 11 o'clock position above the Conv. fan hole, about 8" up. Although on a DF30, the unit is light enough to access from the rear too.

I've changed a handful of relay boards on these units, most recently last week on a DF486 for a bad DBL relay on the small oven.

In either case, you can positively confirm the failure by checking voltage at the board, or continuity from the board through the thermal limit. Bullnoses on these units come off pretty easily for access.

[Rhubarb Tau]

On 11/30/2020 at 5:08 AM, Craig Knight said:

Which elements were you checking? The 18” or 30/36”?

His model (DF304) only has a single oven cavity

[etherhuffer]

9 hours ago, ECtoFix said:

Yes. Fun.

I  work solely on repairing commercial stuff (no residential) and this evening I relished in finding myself addressing the failings of a big ole Hobart "flight" dish machine (model FT900) at a huge hotel. 

Amongst the muck and funk I was surrounded by, an audience of cockroaches observing my "troubleshooting & repair" performance offered little to NO feedback (no laughs, advice...or applause for my successful repair).  INSTEAD, their congregation of little-uns were more concerned with seeking out every nook and cranny as any refuge they could find.  With my being new there, they appreciated the new overhead I provided by scampering underneath my hand-tools, my multimeter, my tool bag...and even ME as I was perched upon several dish racks above that (potentially) vomit-inducing Terra-cota tiled floor. 

YES. I thoroughly enjoyed all of the good and the bad (because I love my job).

****************************************************************************

Sounds like you have the tools and reference material you need to repair your range.  After my looking at the service manual, I'll admit that it appears to be quite a complex appliance on the controls side.  I hope what you find ends up being something simple and you get it figured out. 

Ha ha ha! I just love "helpers" on the job.  My cat had ignored me for days (sniff, sniff) until on my back putting new brushes on Asko washing machine motor. Then it was all about standing on my head and getting fur all over me.....

[etherhuffer]

3 hours ago, AccApp said:

Did you find a popped joint under a relay on the relay board? I had a similar problem on my DF48 and I was able to clean it and resolder it and it has been working for years now.

Ran out of time, going back in to check later. It sounds like relay board is more likely to fail than control board as the solder points take more heat stress

[etherhuffer]

3 hours ago, Rhubarb Tau said:

Sounds like a bad DBL relay or open thermal limit, measurements would confirm.

The thermal limit is on the back, but easy-ish to reach by removing the convection fan. As I recall it's at about the 11 o'clock position above the Conv. fan hole, about 8" up. Although on a DF30, the unit is light enough to access from the rear too.

I've changed a handful of relay boards on these units, most recently last week on a DF486 for a bad DBL relay on the small oven.

In either case, you can positively confirm the failure by checking voltage at the board, or continuity from the board through the thermal limit. Bullnoses on these units come off pretty easily for access.

Yes, bullnose came off ok. Ate up a lot of time with 409, vacuum, and air line cleaning out the unspeakable. Every project has a stopping point as the clock closes in on dinner. Also, the wire connectors were pretty brittle. Anyone use Deoxit spray on connectors? It works wonders on potentiometers, switches, etc. 

 

[etherhuffer]

OK, was going to walk away from this but compulsion took over. The back panel is off, the thermal limiter is not popped up, its down. Ohms about zero on my meter. Trying to see where the ohm rating is supposed to be in the manual, not seeing it in tech section. 

[etherhuffer]

never mind, I am looking for continuity. I have continuity.  YES I HAVE CONTINUITY! I HAVE THE POWER! HAHAHAHAHA

[etherhuffer]

That left the boards, the boards look good, no solder points are burned or broken, so I am done. Time for the pro to come visit me. 

[ECtoFix]

When you cycle the oven's temp control, do you hear (or feel) the relays on the relay board click?

[etherhuffer]

On 12/3/2020 at 3:29 PM, ECtoFix said:

When you cycle the oven's temp control, do you hear (or feel) the relays on the relay board click?

Yes. I do

[ECtoFix]

19 minutes ago, etherhuffer said:

Yes. I do

Well then, sounds like the relay board is getting its control signals to operate.

Take a look at the schematic on page 83 of the service manual.  Use it as a guide to check voltage input to the relay board.  Test all of the L1s while referencing L2 as the common. The schematic shows there are two L1s, an L1-A and an L1-B.  All should read 240v when referencing L2.  If so, the voltage to the relay board is good.

Next, cycle the oven to call for heat so the relays click (energize), then check output voltages FROM the relay board.  Terminal DLB is your L2 output.  Reference it while you test outputs from each of the Pr1 thru Pr6.  If you don't get 240v, then it's very likely the contacts of relay K7 are cooked and you'll need a new relay board.

There's more you can do to verify that, but just do what I've described for now.  I gotta go.

[etherhuffer]

So, it was a relay solder point. Up and running again! I just had an issue with an outlet timer in my house. Pulled it apart and it too was an OMRON relay that had burned. Plus corrosion of flux. Seems to be a universally weak point on boards