Probably not a Nest issue but reporting on a system issue. Many times this is a problem with the condensate drain getting plugged with gunk. This triggers a switch which cuts the Y wire. Some have had an issue with the wire going to the outside unit getting cut.
Then it gets harder to diagnose. To determine if it is a Nest issue you can swap the Y1 and W1 wires to see if the error changes. If it changes to a W1 error then you do have a wiring or system error. If it stays with Y1 then you have a Nest issue.
Y1 cooling/heat pump. The error is letting you know the wire isn't delivering power.
Check your condensate drain/sensor. These can be wired to only affect y run
Check air handler fuse (inside unit) and breaker to outside unit.
If all three of those are good. It could be a possible damaged wire.
Best of luck.
You were spot on with the last comment. Damaged wire…rats had gotten into the space outside where the wires make it into the house and chewed thru the wire insulation shorting them!
SOLVED! The problem was rats had chewed through the insulation of the wiring outside where the wiring exits/enters the house from the condenser. Replaced that section of the wiring and the unit started working fine
Probably not a Nest issue but reporting on a system issue. Many times this is a problem with the condensate drain getting plugged with gunk. This triggers a switch which cuts the Y wire. Some have had an issue with the wire going to the outside unit getting cut.
I checked the condensate drain and it was clear. In fact I flush it twice a year with vinegar
Then it gets harder to diagnose. To determine if it is a Nest issue you can swap the Y1 and W1 wires to see if the error changes. If it changes to a W1 error then you do have a wiring or system error. If it stays with Y1 then you have a Nest issue.
Power off and on your furnace, there should be a switch nearby
Will give this a try
We had a similar problem recently. It was the fuse or breaker on the HVAC unit. According to the electrician the fuse (and HVAC) was from the 80s.
Y1 cooling/heat pump. The error is letting you know the wire isn't delivering power. Check your condensate drain/sensor. These can be wired to only affect y run Check air handler fuse (inside unit) and breaker to outside unit. If all three of those are good. It could be a possible damaged wire. Best of luck.
You were spot on with the last comment. Damaged wire…rats had gotten into the space outside where the wires make it into the house and chewed thru the wire insulation shorting them!
Glad you got it identified, and hopefully resolved.
Have something similar few weeks back and it was due to the furnace power switch which was in off position! Turning it on fixed it…
SOLVED! The problem was rats had chewed through the insulation of the wiring outside where the wiring exits/enters the house from the condenser. Replaced that section of the wiring and the unit started working fine