Fixing Garage Door Opener Range: Ferrite Cores

Not too long ago, a reader reached out to me about a range problem they were having with their garage door opener. He had implemented my DIY smart garage door opener solution using a Shelly 1, but it had severely reduced his garage door opener range. I tested my garage door range, with and without the Shelly, and sure enough, I had some reduced range too. I researched and tried a few different things. The solution in the end? Ferrite cores!

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Garage Door Opener Range Background

I implemented the Shelly DIY smart garage door opener on both of my garage doors. The range on one of the doors wasn’t affected (I did eventually replace this garage door opener and ended up having to use a more sophisticated solution). Over time, however, the range on the other door did seem shorter than normal. I tried the following fixes:

• Replacing the batteries in the garage door opener
• Buying a “long-range” garage door opener transmitter
• Replacing the LED bulbs in the garage with CFLs and bulbs designed not to cause interference with garage door openers.

In the end, all of these devices added a little range, but nothing too drastic. For years, I just let it be. You could open and close the garage from outside of the garage, so it wasn’t too bad. Still, it always bothered me that the range of one of the garage doors was so much shorter than the other.

An email from a reader…

Then a reader emailed me that they couldn’t use my Shelly smart garage door opener solution. After implementing it, they couldn’t use the garage door opener outside the garage door at all! He also told me that when he unplugs the Shelly, it works fine. This piqued my interest.

What I found from my tests

The engineer in me had to look at this again. So, I went out and unplugged my Shelly smart garage door opener and tested it. Sure enough, the range of the opener did increase. I didn’t have it as bad as the reader, but unplugging the Shelly sure improved the range!

So, I assumed something with the Shelly was causing interference.

I moved the location of the Shelly farther away from the garage door opener. Still, the range was decreased.

Now, the 12V adapter powering the Shelly was plugged into the same outlet as the garage door opener. I didn’t have any other outlets close by. I got an extension cord and plugged the Shelly’s adapter into a different outlet. Sure enough, the range increased to the same distance as when the Shelly was unplugged.

The solution: Ferrite cores

Ceedmon 20 Pieces Clip-on Ferrite Ring Core RFI EMI Noise Suppressor Cable Clip for 3mm/5mm/7mm/9mm/13mm Diameter Cable, Black

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Turns out the problem is having the Shelly adapter plugged into the same outlet as the Garage door opener. This is strange to me because I had the exact same setup with my other garage door (both the Shelly and garage door opener plugged into the same outlet) with the same garage door opener model and it wasn’t affected.

Maybe there was something weird going on with one of the outlets. I’m still not sure. But I didn’t want to have an extension cord running along my ceiling so I thought about a solution that might work with the Shelly and the garage door opener plugged into the same outlet.

I noticed none of the adapters had any ferrite cores. Ferrite cores reduce RFI and EMI noise emanating from cables. So I bought a few to place on the cords around the garage door opener and Shelly to see if they’d help increase the range.

Testing the ferrite cores

I decided to test placing the ferrite cores on the adapters of both the Shelly relay and the garage door opener. I also placed them on the wires going from the Shelly to the garage door opener, and on the wires going from the garage door opener button to the garage door opener. I ran tests of range for each of these changes individually.

It’s important to note that in all cases, I placed ferrite cores on both ends of the cords. I found that all of the locations of ferrite cores made some difference. But by far, the most range difference was made by placing ferrite cores on the wires going from the Shelly to the garage door opener. This made my range almost as long as it was without the Shelly.

In the end, I left ferrite cores on the adapters and the wires going into the garage door opener controls. Problem fixed!

Final thoughts

If you are having some garage door opener range problems, be sure to look into using ferrite cores. You should still also check the batteries in your garage door opener remote and try replacing the lighting if they are LEDs. But if those don’t work, try some ferrite cores. They worked for me!