I recently had a Trane two-stage variable speed furnace (model
TUY060R9V3)installed along with a White Rodgers 1F80-261 single-stage
thermostat. My installer noted that the single-stage thermostat,
properly jumpered, works as well as using a White Rodgers 1F81
two-stage thermostat, as the 1F81 model operates by timer in the same
way as the single-stage, properly jumpered, would (i.e., ten minutes
on low fire, then switch to second stage heat).
Based on what I've read and discussions I've had with others, it seems
that a two-stage thermostat would in fact take into account
temperature differentials, etc., in determining when to switch to high
fire, not just time.
Is anybody familiar with this issue, specifically with respect to
White Rodgers thermostats? Apologies in advance if this is an obvious
question to some of you. I am no expert on heating, but it seems that
my two-stage system should be running with a multi-stage thermostat.
Thanks in advance for any comments.