Not sure if this is the right forum to ask or not but I have 2 old 2456S3 ApplianceLinc devices.  I don't think they're dual band. Is that right? And if not, I can't see why I shouldn't just toss them.  Thoughts? 

I keep using them when they still work especially around the Holidays when you need extra modules for all the string lights. 

They're powerline only. If they still work, tossing them would be up to you. 

I still have some in use.

If they still work I would also say keep them.

I have some of the original V1.3. That failed. Load flashed on and off at about a 1 second cycle. I did rebuild them but now retired. My V4 ones are still in use.

What life expectancy of the devices? I’ve still got most original devices install at house 15 years ago. Only recently had two single band dimmerlincs that failed and I replaced.

I bought a box full of dual band devices at one the last 50% Smarthome sales. I thought I’d upgrade single band with Dual Band. Replaced a few appliancelinc and lamplincs resulting in Insteon network becoming /is rock solid so never did wholesale swap of switches and other lamplincs. In fact, I’ve reused a few of the single band lamplincs and appliancelincs to replace equivalent that failed and then recapped broken for future use.