First time posting.
I'm doing some upgrades to our house electrical. We live in a 1950s home. An electrician recommended I replace the old breakers on ungrounded circuits off the house sub-panel with combination GFCI/AFCI breakers. Here are the ones I've purchased: http://w3.usa.siemens.com/powerdistribution/us/en/product-portfolio/circuit-breakers/residential-circuit-breakers/Pages/Dual-Function.aspx. We have a mix of 15A and 20A breakers.
Generally, I haven't had any issues replacing the breakers. I've done several and they all work as expected. However, one breaker slot on the sub-panel is behaving strangely. The slot works as expected with the old breaker. But when replacing the old breaker with the new GFCI breaker, it won't flip into the ON position. It seems that nothing is wrong with the new breaker itself: two new breakers of the same type exhibit the same behavior in that slot, but work as expected in another slot. The instructions that come with the new breaker suggest this issue happens when no power is getting to it, but that doesn't make sense to me since the old breaker works fine in that position.
To be clear, the new breaker doesn't appear to be tripping. It never is able to switch on to begin with.
Does this ring any bells? Any troubleshooting tips appreciated.
EDIT: I was using Seimans Breakers when I should have been using GE Breakers approved for use in my particular panel. After replacing with the correct type of breakers, everything works as expected in all the original positions.