topic Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again. in Nest Thermostats

E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

H8_Nest — Tue, 12 Apr 2022 23:38:20 GMT

Do these crummy things ever last more than a year?

This is the 2nd time one of these thermostats has crapped out and started sending the e103 code.

And yes, I know I have to call someone out, but I also know that they won't find any wiring changes, because there haven't been any, and they won't find that anything has worked loose, because it hasn't, but, because it has been just over the timeframe of the warranty, I'll have to pay to replace this silly thing again.

I am for sure going back to analog, but I would like to have some comfort between now and whenever my AC guys can come and charge me to tell me the Nest unit is bad...again.

I've done a restart and I can get the unit to blow cold air for 10 or 15 min, then the equipment change/wiring message pops up again (exact behavior as the last time it went out).

I've done a reset and couldn't even get the fan to blow in the setup.

Is there some way I can get this thing to run the AC for at least a night and a day until I can get someone to come and verify that it is trashed?

I'm open to anything that will make the thermostat run, even if it destroys the Nest unit - it's gone as soon as I can swing it.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Patrick_Caezza — Wed, 13 Apr 2022 01:59:48 GMT

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

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

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

H8_Nest — Wed, 13 Apr 2022 10:17:30 GMT

Of course it will be tested, but my bet (clearly) is that it is doing exactly what the last Nest unit did before it died - throwing a phantom code that can never be fixed.

If there is a problem with anything but the Nest unit, I will post a follow up.

I did manage to fiddle with it enough to get it to cool the house down below 83 and sticky, but I'm guessing it is taxing the AC with more starts and stops than would be normal.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Patrick_Caezza — Wed, 13 Apr 2022 23:45:54 GMT

The Nest will fail in time if the contactor is falling. The contactor uses too much current and after some time the Nest thermostat's internal fuse fails.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Sheri1 — Tue, 10 May 2022 21:26:57 GMT

Hi Patrick,

What is the contactor? Is this a part in the Nest or the AC unit? Is this something a HVAC person can fix?

Thank you,

Sheri

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

H8_Nest — Tue, 10 May 2022 21:36:54 GMT

Brought out our HVAC company, and though it took two tries, they determined the Nest Thermostat unit had gone bad again. They replaced it with a non-smart Digital Thermostat at no additional cost. Just the service fees.

Glad to be out of the Nest business.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Sheri1 — Mon, 23 May 2022 16:28:27 GMT

Yes, that is what happened with mine. It was also two other things he replaced in the AC unit, one was dead the other was going. If I had my choice I would rather have replaced the Nest Thermostat. It was 10% cheaper!

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Sheri1 — Mon, 23 May 2022 16:30:19 GMT

You are correct. See my response to you above.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Sheri1 — Mon, 23 May 2022 16:36:30 GMT

See my response to Patrick_Caezza above. It is the connector in the AC unit causing the Nest internal fuse to fail. Once the AC guy replaced the connector (and two other issues) the Next was fine.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Sheri1 — Mon, 23 May 2022 16:38:46 GMT

Not the Nest, it is the connector like Patrick_Caezza (below) stated. I found out the expensive way. I wish it was just the cost of the Nest. Once the components were fixed the Nest was fine.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Sheri1 — Mon, 23 May 2022 16:40:16 GMT

Not the Nest, it was the connector in the AC Unit as stated by Patrick_Caezza (below).

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Mistic67 — Sat, 28 May 2022 16:52:41 GMT

I started experiencing the e103 code this season. Last season was perfectly fine. I decided to take a look into this e103 error, which is supposedly an overcurrent condition. I have my 24 VAC, jumpered an ampmeter between the power & Y1. I'm not sure what the surge was, but I can tell you my readings averaged 300-310 mA. I haven't measured the coil resistance, but if you do the math, I have 77-78 Ohms of impedance.

So, my question here is, at what mA reading does Nest consider an overcurrent condition? What is the rating of the Nest internal fuse? In my opinion, 300 mA should be perfectly fine.

Nest 3rd Gen Learning Thermostat T3018US

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

marksastre — Mon, 18 Jul 2022 13:49:29 GMT

#following.

My NEST just spit out the E103 code. No wires are broken or loose, nothing has been changed or moved. Everything was working fine until it going out overnight last night. My AC unit is a brand new Lennox purchased and installed one year ago. Are these NESTs really junk? This is the third time i've gotten error codes over the last year.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

H8_Nest — Mon, 18 Jul 2022 14:02:37 GMT

Switched off to a non-smart thermo and haven't had a problem since.

I'm wondering if there are just some systems (likely older ones) that don't support Nest well - almost like a personality thing.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

Mistic67 — Mon, 18 Jul 2022 21:12:03 GMT

Worth the spare wires, I was able to add the common. That took care of the Nest getting power. The unit was short cycling. It turned out there was a wiring issue in the basement. After 3 junior techs, they finally sent a master, and he was the one that fixed it. Works perfectly now.

But, I do know someone with a multi zone system. He also suffered the e103 issues. He replaced all Nests with some HP thermostats, and hasn't had a problem since.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

marksastre — Mon, 18 Jul 2022 21:31:37 GMT

My AC guys just left here - repaired the unit. They 'think' the 24v wire may have been damaged somewhere. They swapped wires and everything is working. He didn't think it was the contacter, but we'll keep an eye on it.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

michaelmior — Tue, 02 Aug 2022 14:30:25 GMT

Do you mean the contactor? In my case, I tested the contactor and it seems to be working fine.

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

kpentecost11 — Fri, 05 Aug 2022 23:37:05 GMT

Our A/C unit is over 20 years old, we just got the E103 error but nothing has changed. Before I call warranty on the a/c unit itself, is it possible they will just want to replace the Nest and not the whole unit?

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

JoeBland — Tue, 30 Aug 2022 06:04:03 GMT

Everyone keeps saying the e103 code is the contactor ! I call BS. It’s a blown ic in the base

Re: E103, yet again. No changes to wiring and I'm sure the unit has just gone bad...again.

JoeBland — Tue, 30 Aug 2022 05:59:04 GMT

Now! Where do I get a replacement or mine repaired without spending $200+ for a new thermostat or $100 for some used base on eBay?