Like any good equipment the more you use it the more wear and tear it receives. I have two new repairs for the latest model of the Garmin heart rate monitors. These are known as the HRM-Run (Red Pod) and HRM-Tri (Blue Pod). I have another post that covers several of the older straps located at this link

One thing I really like about Garmin is that they have excellent customer service. In today’s world of online purchasing and cost cutting, this is often something that many companies out there just don’t do very well. If you haven’t already, give them a call and tell them about your equipment issue. They don’t list heart rate monitors on the warranty forms or in the phone listing so you will need to select the options for your watch model. I recommend you save yourself the trouble and call Garmin support before reading any further as your first step to any repair.

Garmin recently sent me a replacement O-ring free of charge and all it took was a phone call.

Battery Compartment O-Ring

If calling Garmin didn’t work for you and your still searching for a replacement O-ring for the battery compartment, Read on. After a long search, I finally thought I found what I was looking for. The o-ring size references in the Garmin forums and a few other message boards. They state the replacement size O-ring is 23mm (ID) x 1mm CS. Unfortunately, this is incorrect for this HRM model.

MY wife discovered her HRM-run started acting strangely. I thought it could be the battery so I picked up a new on at the store and got ready to replace it. What I found when I opened the pod casing was that the battery compartment was wet. After reading many forums stating that Garmin won’t replace the O-ring I skipped trying to call Garmin support and searched online to order one that was similar. I ordered 3 sizes starting with the size listed above and the next two sizes down and found that they were all too large. The smallest size (ID) ring that I purchased was a 22mm and was able to fit under the cover but still leaked after a few runs on hot days causing the monitor data to read erratically. This is when I finally called and Garmin resolved my issue in less than a minute.

If you find calling Garmin doesn’t work or just want to source a replacement yourself here is the actual ring details and part number straight from Garmin.

O-ring,19.05mm x 1.168mm, 50A Drmtr, Red Silicone

You can purchase a similarly sized o-ring from

Garmin HRM-Run/Tri Securing Loop

This next repair covers the loop portion of the heart rate strap used to connect the hook when putting it on.

I’ve experienced 2 small issues.

The first is the glue around the loop edge started to peel away. This was easily fixed with some super glue. A fabric glue may work better for flexibility.


The second issue is with the internals of the loop. The strap is made from a flattened tube and the end is made into a loop by folding it back on itself where it is glued and taped to create the area used for connecting the strap. The issue I had was when the tube started separating on the inside. This made it very difficult to take off because the material would get bunched up on the hook as you try and undo it.

I came up with a very simple fix for this. You’ll need the following materials:

1 x Soda Straw (not a used one)

1 x pair of scissors

Glue  – super glue or fabric glue. (you only need 1 or 2 drops)

You need to use a glue that isn’t designed to melt plastics and remember that many super types of glue harden and aren’t flexible. This could cause a hard spot for chaffing if you’re not careful.


Those of you who are very observant will notice that the HRM I’m working on also has a crack in the casing. We don’t know what caused it. Maybe a drop or it got crushed in the gym bag. I’ll be attempting to fix it as well and will update the post once I’ve done this.

Update: The casing repair did not work and I ended up buying my wife a new HRM run. On another note, I have made it my mission to keep my HRM-Tri running as long as possible and have an improvement in the securing loop repair above. the above repair laster most of 6 months before the glue I used gave out. Follow the blog and you will get an e-mail as soon as I post the update. Link to the new post here