E103 - 2nd time in 2 months

[Mbj1218]

Last month I got the E103 error out of nowhere after 2 years with no issue. I ended up talking to Nest support and I did find that one if the connections wasn't solid. I could tell because the gray button was not depressed like all the others. The crazy thing is it's one of the heat wires and I am running the air so why does it care. After that fix it has run about 6 weeks and now the E103 is back. Wire I fixed previously is still in place. I have a nest upstairs too, installed same time and no issues.

I have read all the comments and one thing to try is to replace the nest. If I do that with another nest, do I need to remove the plate with all the connections and put the new one on or just pop on the new thermostat using the old plate? 

[Patrick_Caezza]

The Nest E103 error code means the thermostat has detected an overcurrent event on the Y1 wire. This usually means something is wrong with your system, not the Nest.

One of the most common failures that can cause the E103 error is the contactor in the outdoor unit failing.

[Markjosephp]

Hello there,

I wanted to stop by and see how I could help.

Thanks for the input, @Patrick_Caezza.

@Mbj1218, I appreciate the steps you've taken. This report might have been overlooked for a long time, and your thermostat's internal breaker at its base has tripped at least 10 times. Since we can't isolate a specific problem with your HVAC system or thermostat wiring, the electrical anomalies tripping the Nest's internal breaker may be normal for your HVAC system. When it trips regularly, you can't reliably control your system.

I'd suggest reaching out to an HVAC technician for a system inspection and let us know if you have any other questions or concerns.

Regards,

Mark

[Markjosephp]

Hi Mbj1218,

I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.

Regards,

Mark

[Mbj1218]

Thank you for the reply and follow up. I ordered a contactor online and my son installed it and seems to have done the trick. 

[Markjosephp]

Hello Mbj1218,

Perfect! Thanks for keeping me in the loop on what you've done to have your concern rectified. If anything comes up, feel free to create a new post, as this thread will be locked within 24 hours.

Best,

Mark

[Mbj1218]

Thank you for replying. I purchased a contactor online and my son installed and so far so good.