Popper Coffee Roaster Has No Heat?

The Fix Could Be Simple! A connector may have come loose.

In the last month we have seen a few Popper roasters where they start blowing cold – no heat. The function seems fine, the fan blows strong, but there is no heat.

This was something new, and when we looked at the first unit, the fix was so simple. One of the connectors that goes to the thermal switch on the side of the roast chamber had simply come off.

I am not sure why this would happen, but in each case the fix took less than 5 minutes. Most people might be interested in doing this themselves so here is what is needed:

  1. Get a small phillips head driver, number 0 or 1.
  2. Pop off the 4 rubber feet on the bottom of popper. See Image Below
  3. Loosen the screws under the rubber feet (I leave them very slightly in, as it makes reassembly faster)
  4. Remove the 2 screws on the bottom of popper along the front .See Image Below
  5. Ease the Popper shell off the base – there is a ribbon cable attached but you can wiggle the shell off without undoing it. Don’t yank on it!
  6. You will see the 2 wires going into the thermal switch on the side of the roast chamber, through the opening in the foam insulation shield. See Image Below
  7. Is one off? Loose? Slide back the silicone cover and reattach the connectors. Crimp them on securely with pliers.
  8. Note that sometimes the silicone boot is discolored or heat damaged, These aren’t really critical to the function, so I usually remove them altogether. See Image Below
  9. Reverse the steps to reassemble and you are done!

Replacement Motor Kit Update


Replacement motors are available at Sweet Maria’s now (June 2023)

Finally, the replacement motors for a DIY rebuild of the Popper coffee roaster are here. I created a video on Sweet Maria’s you tube, and there is more information, plus the link to get a kit, on the SM Coffee Library page. And here is where you get the motor kit for $5 .

Listed instructions from the Video Captions

If it’s helpful, here are the instructions listed out, as they are shown in the video. If there is extra clarification you need or a photo that would be helpful, please comment and we will try to add that.

1- remove the 4 rubber feet to reveal screws beneath.

2- remove the 2 larger front face screws with the No. 1 driver.

3- remove the 4 screws under the rubber feet to release the base from the body shroud.

4- separate base from shroud gently tilting at angle toward the  the ribbon wire

5- disconnect ribbon wire and put the body aside.

6 – remove thermal switch connectors and remove insulation jacket.

7 – remove 3 screws holding roast chamber assembly to base plate

8 – remove 3 machine screws holding white fan shroud to metal roast chamber.

9 – remove 3 ceramic spacers to prevent damaging them.

10 – pull the fan off the splined motor shaft 

11 – remove 2 small motor mount machine screws – motor is free now

12 – pinch the insulation above the spade connector to help release, while gently pulling side to side and upward. 

13 – apply the 2 strips as in the video, not covering any openings in motor casing

14 – insert motor back into white housing, lining up holes in motor with where the 2 mounting screws will go.

14a – (oops) reattach motor with 2 screws, and tighten while pushing motor in place from the back. Don’t overtighten…

15 – push fan down with firm even pressure. test that it moves smoothly

16 – replace ceramic spacers. (added: These are very important to hold fan and heat coil in proper position!)

17 – replace 3 machine screws holding metal chamber to white motor mount.

17a – (added: You will be connecting the red and black wires on the new motor back to the PCB board exactly as they came off; black wire on the lower connector, red wire on upper connector. If you reverse these the motor functions but cannot roast much coffee because (I am pretty sure) the fan will be spinning backwards!

18 – slide thermal jacket on and re attach connectors to thermal switch, pinching them on if they feel lose at all. (added: if they seem loose at all, crip them on a but with pliers. If they aren’t well connected, full power is not getting to the heat coil, and your roasts will take too long / bake.)

19 – Inverting popper, attach base to chamber with 3 screws.

20 – reconnect ribbon cable.

21 – Reseat the shroud on the base, keeping one hand in top hole of roaster to guide it. Don’t force it!

22 – Replace the 2 larger front screws and 4 screws under the rubber feet, and replace rubber feet.

23 – Test your work… hopefully that motor purrs at an even clip and you have 250+ roasts more…

Repair motors for the Popper coffee roaster have arrived

Popper coffee roaster repair motor

For those willing to replace their old dysfunctional motor with a new one, a 20 minute task can result in new life for the Popper coffee roaster

Here’s a quick update that the motors are here, and we can prepare to send them soon once we have assembled the small kit and made a step by step repair video.

Swapping the motor out is pretty simple, a 15-20 minute task. But doing it with some care can have a much better result than rushing through it. So we will get a good video together to guide through the process to get the best results!

Popper Coffee Roaster – What Does a Bad Fan Motor Sound Like?

Popper is a coffee roaster

We have had some issues with the Fan Motor in some units. Here’s how you know if it’s happening to yours!

We have had some issues with the fan motor failing to turn at a constant speed. It has cropped up in about 30 roasters (out of 1800 units or so!).

It seems to happen after 30-50 roasts or more, which is why our QC team didn’t catch it. This video demonstrates the sound of a good fan motor and a bad one, and tells you what to do to get roasting again!

If you’re Popper roaster starts sounding like the Defect Unit I show in this video, STOP using it though! And email info@sweetmarias.com for more…

Popper Fan Motor Problem – Good vs Bad

Popper Fan Knob Repair

Popper Fan Knob Repair DIY

Don’t be rough with that knob! We find people are twisting it past the stopping points: If the fan knob starts to feel like it is not “clicking” into position at Off, Low, or High, it might break soon…

If the fan knob is turned past the Off or the High position stops, it can break. When it breaks it spins freely on the post, so it can’t be used to turn the machine on or off, or change air speed.. Bummer.

This is caused by being handled too rough, turned too hard, especially when the user believes the range of the Fan knob is the same as the Heat knob, which turns in a 180 degree arc. It isn’t. The fan knob turns in a 90 degree range. But honestly this would be less of an issue if the way the knob grabbed the post was stronger. We will fix that in the next manufacturing run!

The good news is that it doesn’t damage the post that the knob attaches too, nor the function of the machine … just the knob itself.

The bad news is that the knob doesn’t just pull off the post from the front of the machine. It is “trapped” behind the front plastic panel. So you have to take the machine apart a bit to get at the knob. You can either get a used replacement knob from us , or even just opt to take it off and use the machine by turning the post directly. It also seems that other types of knobs will fit on this “half moon” shaped post. Get creative!

Also, getting at the knob isn’t hard, you just need one small screwdriver and the rest is pretty easy. I can do it in 5 minutes, but it probably took 15 minutes the first time to complete this repair. See below for the video version of this repair or follow this link to see on youtube directly

Video DIY Fan Knob Fix for Popper Coffee Roaster

Video Version: Popper Fan Knob Fix