Said It Here

Why is one newly installed thermostat not turning on?

A newly installed thermostat or device can fail to power on in a single location even when wiring and power appear correct. This leaves users unable to get the equipment working and forces them to troubleshoot underlying electrical or hardware incompatibilities.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Having a journeyman electrician take over troubleshooting

In their words

Unedited, most upvoted first, each linked to the thread it came from.

“Installed disconnects and cord ends for a few 480v portable AC units. 2 work, 2 do not power on.”source ↗

“I found the drawing online and was curious if having the wrong phase rotation could cause the phase protector to not allow power to the PCB?”source ↗

Math_NotEvenOnce · r/hvacadvice · 2 upvotes

“Hey all, I just installed new Sinope smart thermostats in every room of my house. They all work except in 1 room. I have replaced the electric baseboard and the thing still won’t turn on.”source ↗

“I’m very much so at a loss right now.”source ↗

NeverKnight-22 · r/askanelectrician · 1 upvotes

Where this came up

r/askanelectricianr/hvacadviceelectricalhvacsmart homethermostattroubleshooting

People with this problem also raised