Do the Y and C wires look correct?

[saurabh9]

I just moved into a new detached house. I have a older generation learning thermostat which I plan to put here. The house currently has a Honeywell thermostat. I opened it, and can see 6 wires.

Question 1: If you see the attached picture though, I see black wire going to Y and orange going to C. Is this possibly swapped, or can this be how this house is setup? Anyway for me to check if the current wires are correctly connected, before I move them to Nest?

Question 2: I see a wire going to W2. What can that be, and how do I test that it is doing what it might be designed to do?

[Houptee]

What type heating system is this? Gas hot air furnace or a all electric Heat pump with A/C?

The colors are not standard for this installation but could be ok otherwise the existing thermostat would not be working at all.

W1 and W2 is stage 1 heat and stage 2 heat

Y is what triggers the AC system to turn on. Normally it is Yellow wire.

G turns on the Fan usually green wire.

C is Common and usually Blue but could be any color they wanted to use or had left in the cable.

I would wire it same way it is now to the Nest since the system is currently working properly with these color wires.

[saurabh9]

I am in Canada, and this is a 2018 built house to fairly new. I can see the A/C box outside the house. I can see the big furnace in our basement...so that must be hot air gas furnace I believe?

[Houptee]

If heat and AC and fan work normally with the old thermostat then just connect the wires the same way to the nest to the same terminals. During setup you tell the Nest it is a hot air heating system with 2 stages heat with AC.

[Jeff]

Hi, everyone. 
In an effort to keep content fresh on the forums here and prioritize current issues, I'm going to go ahead and close up this thread. If you have any outstanding issues from this post or any other problems, please feel free to open up a new discussion.
Thanks,
- Jeff

[MadGasser]

In order to determine what wires are what you'll need to go to the furnace and open the door to see what wires are landed where. They should be the same on both ends. I'm an HVAC professional. Any other help needed just ask.

[gregshaffer19]

What you have is a tech that used  uncommon wiring colors due to what was in the wall, looks like a heat pump, w1/w2 are your auxiliary and possibly emergency on w2 or second stage auxiliary, that brand of t-stat is known for advertising it does aux heat but in installer set-up the menu can’t  be accessed. Some people tie all the six heat together in the air handler, Turn the heat on for the customer good warm heat great selling point until you get your first electric bill the way I like to wire mine is in a condition like yours or it’s probably a 15 kW heat strip I’d like to use the 5 kW section for auxiliary and the 10 kW for emergency save lotta cash that way