i have to ask…where you ever able to verify, before the power outages, if the T-stats would power on without the batteries? Reason I ask is to be sure the wires are landing on the correct terminals.
Absolutely. The thermostats were working perfectly without batteries.
I do remember, about two years ago, when the Tech at Alarm.com navigated me through the set up and we had to “tell” the thermostat how to use the common wire for thermostat power. It worked perfectly?
See attached photo of wiring. The green wire leads to the common at the boiler. I don’t have central AC…just heat.
I do remember, about two years ago, when the Tech at Alarm.com navigated me through the set up and we had to “tell” the thermostat how to use the common wire for thermostat power. It worked perfectly?
During setup you would need to learn the thermostat into the alarm panel while it is powered via AC in order for it to act as a Z-wave repeater and operate on full power mode, otherwise it would go into power save mode and not act as a repeater if learned in while running on battery power.
That doesn’t affect whether or not the Tstat will power on, just how the Z-wave radio behaves.
So you have tested the AC power between RH and C? To be sure, set your multimeter to test AC, then test with the leads connected to RH and C wires. Is it 24VAC?
From the description it really sounds like the common wire may be loose or damaged at the boiler end.
Use wires from the 1st thermostat (which uses the common perfectly) - still no power
By no power, do you mean the thermostat did not power on when attached to the wires?
Are you cutting power to the Boiler before making wiring changes? Attaching live wires to the thermostat terminals can cause shorts to occur.
When the 2nd Tstat is wired to the circuit that was previously delivering voltage, did you test to make sure voltage was being delivered at the time? Switching live wires might also throw breakers or blow fuses depending.