A carrier 58TMA085-12. 2 stage 80% down flow furnace. the filter is a little dirty and when the limits open it drops 24v at the R terminal, thus causing the power to the thermostat to drop out.
Is this normal? I don't recall ever seeing this. Its in my dads house and I'm not going to lie the filter gets forgot about. If it was normal I'm guessing it would've showed up in the last 8 years of having this thermostat.