I just wired my Nest Learning Thermostat to my 2-stage furnace. While doing the built in test on the Nest to verify function, I cannot get the 2nd stage heating to work properly. Single stage (1st stage) works properly.
At the furnace, in first-stage testing, I see voltage at the W1 wire.
When I start the second-stage test, I still see voltage at the W1 wire, but no voltage at the W2 wire.
In an attempt to see if it was affected by the built in algorithms in the Nest, I left the 2nd stage heat test run for 15 minutes to see if it eventually kicked in the W2 voltage... but there was no change and the W1 wire remained high and the W2 wire sill showed no voltage.
Neither the Nest built in test nor then furnace show any error codes.
Removing the W2 wire from the nest connection allows the system to run as a single-stage heated (as expected), but it would be nice to get full functionality from the system.
Any ideas?
