Heart rate monitoring occassionaly stops working

In the meantime I upgraded to a Fenix 6 (after switching back to Fenix 5 for months). The Fenix 6 does not have the issue at least on my wrist. 

I recently purchased a 245M about 3 weeks ago and have had the same issue from day 1. The heart rate monitor only works 50% of the time and on most nights stops working entirely after an hour or two of sleep. Very frustrating when that is one of the main reasons for buying the watch in the first place. I have done firmware updates and reset the watch several times but have had no luck fixing the issue.

I had the same problem with my 245 i bought last year, reset, updated the software and did everything possible suggested by the dealer and finally they replaced this with a new watch and it is working fine. I think there are hardware issues with certain batches. I bought a 945 recently, and it is working fine and so i think this is most likely a hardware issue. 

Just fyi - I now switched to a Fenix 6S which also has the new OHR but does not have the OHR monitoring issue as the 245 (at least in my case). So it looks like there is something especially wrong with the 245. 

I'm having the same issue. I bought my FR245 a week ago and HRM it's been working intermittently. If I try to measure Breathing for example, appears on the screen a message that say I should check the position of the clock in my wrist. But it hasn't move nor it's loose. Taking it off and putting it back again not always work. Neither turning off and on HRM from Garmin Connect.

I wish I could turn the Wrist Heart Rate setting from Auto to Always, maybe there's where the solution is.

The firmware is 4.4.

I have the same problem: so far out of 6 activities (running) my FR245 stopped working by itself... 3 times. Very frustrating and irritating !

Interesting feed this guys. Glad I found it today. 

Previously, I've had a FR245, FR45 and VA4S all returned over a period of a year and a half because of the regular OHR drop outs. It's frustrating that you have to keep showing the sensor some sunlight for it to kick back in and turn on, just for the whole process to restart again. 

Surely, this watch must know it's on a wrist with all the movement, right? If that's the case, I'd then expect the OHR to kick back in again to re-establish a signal. But no. 

Interestingly enough, I have an old VA3 that works well! On the occasion it looses HR signal, it will kick in nearly immediately on full strength LED to relocate - and surely enough it works!

Garmin, I'm afraid I won't be returning to your products if all of the new devices have the same hardware/sensors. 

I have had this same issue with my 245 music on day one! the monitor was working fine, did a workout, went for a swim. That night it did not register my sleep at all. the monitor measured HR for a few hours in the morning then dropped out completely and i couldnt get it to turn back on. i have reset machine, turned off and on, reset garmin connect all didnt work. I went back to retailer and exchanged for a brand new one again but after reading this im not too optimistic. will give it another day before i go get a refund.

I think I have the same issue here... I'm using the 935. It records properly the heart rate when I exercise, but my daily monitoring function does not look good. It is also not recording my sleep parameters.... Should I reset?

Got the same issue, unfortunately it has no fix, my watch is only good for its GPS now...