e74 error I do not have heat please help

[Vidangos]

Need Help to solve this problem with my old system I live fine for 30 years, know this one works only two years and is broken  

[sporfrog]

E74 indicates a problem with power to the thermostat often on the RH wire.

While it could be the thermostat, it could also be the furnace or HVAC unit. Perhaps the circuit breaker is off? Or maybe there is a service disconnect off at the unit (something like a light switch)? There may also be a blown fuse in the furnace or a problem with the circuit board. Or maybe a loose connection on the wiring terminal?

At the thermostat check the wiring connections to make sure one of the wires on the backplate has not come loose or is damaged.

Feel free to send a photo of the wiring for the thermostat to verify if the connections look correct.

[MelbaDT]

Hey folks, 

Thanks for answering to this, sporfrog.

Vidangos, thanks for posting and welcome to the Google Nest Community. Do you still need help with this? If yes, have you had the chance to check sporfrog's suggestions above? If yes, how was it? 

Best, 

Melba

[MelbaDT]

Hey there, 

Checking back in — how's your Nest thermostat now? 

Best, 

Melba

[MelbaDT]

Hi, 

I haven't heard from you in a while so I'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community.

Best, 

Melba