Dead Bosch wall oven- help needed

[wdfifteen]

I moved my 5 year old Bosch wall oven to a new location and now it is DEAD. Totally unresponsive. It has 220 volts across the power wires (black to red) at the junction block in the oven. Online searches rule out thermal fuse (oven light should still work). I have power and I think I have a good thermal fuse, so where do I go from there?

[billybek]

Do you have a neutral wire?
These usually utilize 120 vac to run the electronics and relays.
Did you actually see 220 vac at the terminal block with a meter?
The reason I ask is that I have seen a few electricians wire in a new plug for an oven or drier only to find that they put the both poles of the breaker on the same phase within the breaker panel.

[wdfifteen]

Originally Posted by billybek

Do you have a neutral wire?
These usually utilize 120 vac to run the electronics and relays.

Hmm. I didn't check that. I'll get back to you.

[dad911]

As Bill said. Newer appliances have 4 connections. red & black, white and ground.

Did you measure 220 across R&B or 110 each to ground?

[wdfifteen]

This has always been a 3- wire connection, so the ground is not used. Last night the voltage between the black and red was 220. Now it it 250. It's 125 between the black and white and the red and white.

[dad911]

If there is a bare ground wire, it should tie to box, which should be grounded to main panel. Either directly with a wire, or if it is older construction, EMT pipe or BX shield.

Model number, and I'll look it up.

[T77911S]

the ONLY thing you did was move it and it died?

did you wire it back up correctly?
remove wires and check power at the wires. BE CAREFUL
are the connections good. you can have 240/120 and not have the current to run anything. check both ends.

is there a fuse on the circuit board of the oven

[JavaBrewer]

How hard would it be to connect it back to the original power outlet? That would immediately identify the trouble spot, ie the oven itself or the power source.

[wdfifteen]

Originally Posted by T77911S

the ONLY thing you did was move it and it died?

Yep. Unplugged it from one wall outlet and plugged it back into another one in the new house. Power supply is not the problem. The voltage I quoted above was checked at the connector block where the cord is attached to the oven.
Im afraid it may have been dropped hard by the movers, but I don’t see any external damage.

[wdfifteen]

Originally Posted by JavaBrewer

How hard would it be to connect it back to the original power outlet?

Pretty hard. It’s 60 miles away.

I called a Bosch repair tech. They are hard to find. Bosch is apparently pretty stingy with tech info and doesn’t like to discount parts to independent repair techs.

[dad911]

Can you dig up a schematic? What's the model number?

[wdfifteen]

It’s either an HBL 54 or HBN 54. Owners manual is for both.

[dad911]

Originally Posted by wdfifteen

It’s either an HBL 54 or HBN 54. Owners manual is for both.

https://www.scribd.com/document/320831191/58300000139357-Bosch-300-500-and-800-Series-Wall-Ovens-Service-Manual

[bickyd]

please call a real electrician.

[wdfifteen]

Thanks Dad. I've been through it down through the "Power Wiring Path" block and everything checks out. I have too many projects on my plate to dig any deeper into this. The Bosch guy is coming tomorrow. I was hoping it would be something simple that I was overlooking. Thank you for the help.

[wdfifteen]

Originally Posted by bickyd

please call a real electrician.

An electrician isn't going to fix my oven.

[bickyd]

Originally Posted by wdfifteen

An electrician isn't going to fix my oven.

An electrician will show up with a multimeter and should be able to tell where the problem is by following the sequence of operation. I am only concerned with your electrical safety. No offence sir.

Sent from my SM-G903W using Tapatalk

[dad911]

WD knows his stuff. And his limits.

And we wouldn't tell someone with an car problem to call a mechanic...

[wdfifteen]

Problem solved!



The Bosch guy came and looked at the oven. He took the top off and checked the voltage across the power lines and the terminal block. "You've 240 volts between the red and the white wires!" My response was alarm, as you can imagine. All I had ever measured there was 120. He brought me over to look, and by then there was 0 volts between red and white. 240 red to black, 0 black to white, 0 red to white, take a second to sneeze, and then 240 red to white.
The tech guy bailed on me, but took a check for $80 with him.
I took the male plug apart AGAIN, with some idea what to look for this time and sure enough, the green ground wire was clearly under the screw connected to the neutral lug. On the other side of the screw, were it was harder to see, the white wire had come loose and was floating around, connecting with the neutral lug, or open, or laying against the black connector, depending on how you moved the cord around.
It was my error, I just didn't take a thorough enough look around when I looked at the connections.

[T77911S]

I thought it was all hard wired in. not a plug in.

great.
I spent more than that on a ground wire for the FI on a Volvo one time. and I removed it.(unknowingly)