Ok, first a little history. Have a Lennox XC21 with a variable speed blower. Two zones. I attempted to use a NEST stat(I don't want this to turn into a debate on the NEST stat) on the upstairs zone. The stat worked beautifully during the winter months, but as soon as I needed A/C, the problems started. The stat went into a delay mode. Nest support attributed it to lack of a C wire. So, they had a tech respond and hooked up a C wire. Still no joy. Nest is looking into the compatibility issue. So, while I would like to use the NEST for my own reason and it does not look like I can, what STAT would you recommend to be used on my upper zone. Thanks!
PS: I would prefer this does not turn into a NEST debate, but would be more then happy to discuss the issues I am experiencing. Thanks again!