topic Replacing a Lennox thermostat Does W2 or Y2 go to the O/B terminal? in Nest Thermostats

Replacing a Lennox thermostat Does W2 or Y2 go to the O/B terminal?

clive_bob — Mon, 09 Jun 2025 16:16:51 GMT

I have 7 wires coming from my Lennox thermostat. There are only 6 terminals on my 3rd Gen Nest. The manual says if I have a W2 or Y2 to insert in the O/B terminal. I have both W2 and Y2. My system is gas forced air. Does W2 or Y2 go to O/B?

Thank you in advance!

Bob

Re: Replacing a Lennox thermostat Does W2 or Y2 go to the O/B terminal?

Patrick_Caezza — Mon, 09 Jun 2025 22:03:12 GMT

@clive_bob

Can you post a picture of the original thermostat's wiring here?

If the camera icon isn't present yet, you can use the imgur.com upload site and post the link it provides here.

Re: Replacing a Lennox thermostat Does W2 or Y2 go to the O/B terminal?

clive_bob — Thu, 12 Jun 2025 13:39:37 GMT

I found my answer. W2 is for a heat pump. Y2 is for non-heat pump. Thanks for your assistance.