Help Please: Diedrich IR-12 not sparking

[jenkruiz]

hey there:

My Diedrich IR -12 is not sparking. Machine is clean and has been working fine. any suggestions would be helpful. New to this community and been roasting for 2 years.
Thanks

 

[nicholasnumbers]

Hey all!

My name is Nick. I'm local to Jen and work at a coffee roaster not far from her shop. I headed over there last night to try and help her out. I can try and provide some clarity, and if those more experienced than me can help me out it would be greatly appreciated!

I should mention: This machine is a 1993 Diedrich IR12. The internals are a little different than what I've seen before.

So typically when an IR won't ignite, it's an airflow issue. I went right to the vacuum sensor and jumped the wires together to the normally open terminal. After I did this, I got a click at the igniter. That told me that it was probably a cleaning issue. I removed the metal tube to the vacuum sensor and did my best to clean it out (blew through it as hard as I could). I couldn't get the entire tube out due to the way it was bent. I'd have to pull the electronics compartment out and wanted to save that as a last resort.

Cleaned tube, replaced wires back to normal on the vacuum sensor, buttoned roaster back up. Now the pilot would ignite, but the burners wouldn't light. Progress, but not there yet.

It was hard for me to see inside the roaster to determine if the igniter probe was in the right spot. Jen said it was adjusted previously.

Does the gas valve need a certain amount of airflow to trigger opening in this machine? We tried adjusting the flow but the burners still wouldn't ignite off of the pilot.

So to me it's either:

1) A cleaning issue (Not enough airflow to open the gas valve to the burners / poor airflow in the roaster which is deflecting the flame away from the igniter probe)

2) The igniter probe is bad

or

3) The gas valve is bad

Here's the electronics compartment:



Can anyone tell me where to go next? Should I just pull the drum cover off of the top of the roaster to get to the igniter probe?

Any help is appreciated. Thanks so much for reading.

Nick

 

[PinkRose]

Wow Nick! That was great of you to go over to try to help her Jen out with her roaster.

Thanks for sharing what you found.

I hope some of the members of this Forum can help you figure out what to do.

Rose

 

[nicholasnumbers]

Wow Nick! That was great of you to go over to try to help her Jen out with her roaster.

Thanks for sharing what you found.

I hope some of the members of this Forum can help you figure out what to do.

Rose

Thanks Rose.

I spoke with Diedrich and they gave me some clues on how to proceed. Heading over there today to drop the burners / pull the cover off of the drum and systematically figure out the damaged component. It's either the ignition module, the gas valve, or the ignitor probe. I wasn't too far off in my diagnosis. If the ignition module is sending 24V (which I can check with my multimeter), it's more than likely the probe.

Nick

 

[nicholasnumbers]

Thanks Rose.

I spoke with Diedrich and they gave me some clues on how to proceed. Heading over there today to drop the burners / pull the cover off of the drum and systematically figure out the damaged component. It's either the ignition module, the gas valve, or the ignitor probe. I wasn't too far off in my diagnosis. If the ignition module is sending 24V (which I can check with my multimeter), it's more than likely the probe.

Nick

Got little to no AC voltage readings over the PV to MV/PV line on the ignition module, and a reading of dead 0 across the MV to MV/PV on the ignition module. Got 25VAC just fine out of the transformer into the module itself; so it looks like the module is dead.

Have a new one coming in the mail. Hopefully this takes care of the issue!

Nick

 

[PinkRose]

Got little to no AC voltage readings over the PV to MV/PV line on the ignition module, and a reading of dead 0 across the MV to MV/PV on the ignition module. Got 25VAC just fine out of the transformer into the module itself; so it looks like the module is dead.

Have a new one coming in the mail. Hopefully this takes care of the issue!

Nick

Hi Nick,

Thanks for the update. It sounds like your diagnosis and treatment of the problem will work out soon.

Rose

 

[Franciskoh]

Hi Nick thanks for the sharings, its really a piece of excellent information for me. Great job Nick!

 

[nicholasnumbers]

Hi Nick thanks for the sharings, its really a piece of excellent information for me. Great job Nick!

Glad this helped you! I replaced the ignition module, and it opened up the gas valve to light the burners off the pilot.

Everything's back to working again.

Nick