Google nest thermostat error e73

[Danielth77]

Why my Google Nest thermostat is showing no power on the Rc wire when there’s power? It was working perfectly fine and then the E73 popped up, I removed the Google one and installed a cheap analogy thermostat, and works. I re-installed the nest and the error comes again. 

[gmelanymelissa]

Hi @Danielth77,

Thanks for posting here in the community. I’m sorry to hear your Nest Thermostat got an E73 error. Help's here!

To better understand the situation, I'd like to ask a few questions:

• What Nest thermostat model do you have?
• Would you mind sharing a photo of your wiring configuration?
• Do you have a conventional or a heat pump system?
• When did your system last receive a professional maintenance check?
• When did you install the thermostat? 

In the meantime, here are a few things you can try:

• Before you start, please turn off the breaker for your HVAC system.
• Check if the air filter is clean and replace it if necessary.
• Check if the drip pan is not overflowing.
• Check if the drain tube isn't clogged.

Keep me posted.

Regards, 

Melany