Garmin HRM Dual transmission issues

Hi all,

Ive been the proud owner of a HRM Dual for all of one week, and couldn’t get HR transmitting into TR on my…second use.

Why do I think buying more kit will make things simpler/easier? :sweat_smile:

HRM showed paired on the iPhone settings, shows paired in TR, displayed an unchanging 77 bpm.

Paired it to Garmin edge as well…failed to pair.

Unpaired in TR, repaired, no change.

Turned off Bluetooth on iPhone…paired automatically to Edge. Displayed HR on Edge.

Turned on Bluetooth on iPhone, paired to iPhone…stops displaying on Edge.

And so on. In the end I recorded in TR without HR and on the edge with HR.

It seems like a Bluetooth issue, but the whole point of the Dual is to be able to pair with two devices on Bluetooth. The Garmin can use ant+ anyway…except it isn’t.

The simplest solution (and best) is to connect to the Edge by ANT+ (after disconnecting BT connection on the edge). Then you will have BT to TR.

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I forgot, HRM DUAL has one ANT+ and only one BT connection. So, you cannot have two BT connections at the same time.


I have the same issue with my iPhone/HRM-Dual that you have, Garmin replaced the first under warranty, and the second one worked for like a week, then it started doing the same thing. I’ve contacted TR support and was sent to Garmin and Garmin Support was no help the second time around. It’s a HRM to iPhone issue as it works via bluetooth to my apple tv and laptop, but not to my iPhone(in seperate tries, I’m aware I can only have one BT connection at a time)

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Great - How do I tell it which protocol to use?

I don’t believe so:

“ Update: Turns out the Garmin HRM-DUAL can indeed do dual Bluetooth as well. Initially when I asked Garmin they said they were limited, but they re-confirmed today they initially misspoke and it will indeed do dual Bluetooth Smart connections, as well as the ANT+ channel. And in fact – I’m able to validate exactly this on my strap.” - DC Rainmaker

I don’t remember exactly but I think there is some indication that the connection is ANT+ in the description.
You are correct on the HRM-DUAL.

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I have no problems pairing my HRM Dual to my edge/watch via ant+ and to other devices via BT.

It allows for two concurrent BT and unlimited ant+ connections… that said, you may be paired to your edge via BT and another app/device via BT as well.

Turn off every device in your house and then just turn on the two devices you want. Connect to those. If that works, it was connecting to something else first.

I use a dual. I run TR on my MacBook and run a Garmin Indoor ride on my 1030 simultaneously. I also connect the 1030 to my iPhone for Xert data field updates via Garmin Connect. If I unlock the iPhone before I connect to the MacBook and 1030, I have issues. If I connect to the MacBook and 1030 first (look for HR on both devices before I click start), and then open my iPhone with Garmin connect, everything works fine.

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I have an issue that fits the title but isn’t quite the same…

I’ve had a HRM Dual for a few years, worked great until a few days ago when it wouldn’t connect to my Edge 830.
Trying to troubleshoot it today it turns out it won’t connect to my Fenix 5 or TR either. TR is a win-PC with ant+.
Replaced battery but no change so I figured it’s dead for some reason.
Went by a lbs and picked up a new one. To my surprise - nothing. Can’t pair it to anything either!

So assuming I still have a heart rate, and it definately felt like during The Priest +4 today, what am I missing?

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did you use a new strap? or just the ‘puck’?

Relevant question.
Both sensors on both straps

Try installing the battery backwards for 30 seconds(no need to screw the unit shut, just hold it there.) this will short both leads out and cause any capacitors to discharge, then re-install the battery normally.

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It is, perhaps, a different name for each channel? Such as some additional digits at the end?

Is the pc or fenix able to pair anything else?

If a brand new Duak isn’t working it must be the other devices or the environment - are you working out in a Faraday cage? :slight_smile:

Fenix and Edge connect with the phone (BT) and Favero Assioma pedals (ANT+).

Have you done the “shut everything off and just pair one thing” test?

Example - turn off the Edge, go a few streets from your house, turn off your phone, turn off your watch, and then turn on the Edge and try to connect to the Dual

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Yes, every device off, phone I just turned BT off. No change.

One more thing I can think of doing is plugging the Garmins into Garmin express and let them run an update check. But that still doesn’t explain why TR can’t pair…

right. ANT+ is broadcast, not single pairing.

I’m at a loss. The only time I’ve had that problem (Wahoo TICKR, multiples of them) the HR< is dying or dead. I have one that broadcasts when dry and unused, but once it starts to heat up, it dies. It could be some leaking seals and sweat getting in, can’t be sure.

but, you have a new HRM, so I have no idea. For the Edge, did you try both ANT+ and BT? Same for the PC?