Reprogramming old v1 C-Bus relays

I'm looking at some work which may require making changes to dozens of RELAY4 modules. Given how long C-Bus v2 has been around these units much be well over 20y old.

Am I likely to face any significant issues making changes to them? Eg flash write failures etc? I've made adhoc changes to them elsewhere without issues but not in sufficient volume to do a proper risk assessment.

If failures are more than a remote possibility, what form would they likely take?

 

The old V1 relays are particularly resilient. They didn't contain power supplies that are typically what fail. I've replaced probably 20+ din-rail units over the last 5 years and only seen 2x 4 channel old style fail (one was full of ants)... I still have 3x relays and 2x dimmers in my roof space and they're still going strong. Installed them in 1999.

The failure I saw was chattering relay that was intermittent.

 

Good to know, thanks!

Now that you mention it it's the separate v1 power supplies we've had to replace elsewhere due to failure, not the relays. Where they've been replaced it's just because we needed extra channels and there wasn't space to add a new v2 unit alongside.