Garmin HRM Pro Plus strong offensive odor emanating from the chest strap

The same for me. He stinks after 2 months so extremely that he is to smell through my shirts. Even the room in which I keep him stinks terrible.
Always rinsed with water after use and occasionally washed off with soap.
Absolute no-go.

I switched from Dual to Pro because of the smelling. It was the same...

Hello,
I also have the same problem, it happened overnight, shortly after I changed the battery, the HRM has just 2 years...

Hi all,

I have the same issue. Since August, I've been using the HRM Pro Plus strap and put good care into it. A day ago, it started smelling like a burned electronic, so I thought something was wrong with the device. However, it works just fine, the battery seems to be okay too...thank God I found this forum, as I thought I was going insane. 

I can confirm that it's under the main module and only the strap smells like that, not where the battery sits. 

It's a bummer, as I bought this with the Forerunner 965 and all was great until this smell came up. 

Have you spoken to Garmin Support , they are normally very good at replacing defective items

Haven't noticed it on my strap.

I have, hoping they'd have a suggestion for how to clean/strip the smell out. They replaced the strap - which I **really** appreciate! But I haven't used it yet and am still using the stinky one because I'm afraid the new one will do the same. I'm currently trying a different mix of things to soak it in after each workout now until I find one that seems to help, so I can try to keep the new one smelling fresh once I figure it out..

Hi, I have the same problem. At the beginning I thought that my cat pee somewhere in the room until I realize that was my Garmin HRT monitor. It’s is a very annoying odor!! I don’t know if there is something I can do to fix it.

I can stand that smell but my question is if there is something more than the odor. What if there is something harmful to the lungs or the skin. 

There's an update from me.

I just came back from the local Garmin Repair shop and they told me what other people have already shared in this post - the smell comes from the sweat build up under the main module, which apparently oxidizes in contact with the other part of module. They said that the device works  which is indeed the case and that the guarantee won't cover this, unsless there's functional damage....also, they assured me the same odor will eventually come up, even if they give me a new one.

Just as I thought  this is a design flaw and there's nothing to worry about. Still, it's very unpleasant, so I might purchase another one from a different brand and see how this goes.

Probably, because some people sweat much more than other the smell varies from person to person. 

Unfortunately, that is not true. The material itself smells. I contacted Garmin and they sent me a new device after I described my problem.
But the problem is just sad for such expensive hardware.
And I don't have sweat problems with any device except this strap!