Hi all, hope you'll bear with me and my amateur knowledge or lack thereof :) I have a 3rd generation Nest thermostat that is successfully hooked up to my home furnace (which also has central air conditioning). I also have a Generalaire 1042 humidifier that is on the furnace, hooked up to an old manual humidistat via a solenoid. I'd like to connect things so that the Nest can control the Generalaire humidifier. I've done a bit of reading here and elsewhere on the internet, but still just have a few questions--some to confirm my knowledge is correct, and some because I don't know the answer :) Hope you can help.... 1. My understanding is that because the Generalaire 1042 doesn't have a transformer, no relay is required. Is that correct, or do I need to install a relay? 2. This may be an obvious question, but...what exactly should I buy in terms of the physical wire that will run from the Nest down through the wall to the lower floor and connect to the furnace and the solenoid? I know very little about physical wire other than what the term "gauge" refers to :) 3. Is this wiring diagram how I have to wire it (minus the HRV, which I don't have in my house)? [URL]https://www.doityourself.com/forum/attachments/thermostatic-controls/28014d1394326133-nest-my-generalaire-1042-humidifier-screen-shot-2014-03-08-7.41.57-pm.jpg[/URL] 4. What equipment do I need to turn off at the breaker when doing this install, and at what point in the installation process? It's really cold here, so would prefer to be able to leave as much equipment running and heating for as long as possible while installing this. Thanks all!!

About a week ago, I pulled the face off the thermostat to touch up the texture around it. When I put it back on, I later got a "no power to Y1 warning). I assumed I knocked the wire loose, but now I'm not sure if it's related at all or just a coincidence. I disconnected all of the wires and reconnected them several times. It didn't work. I tried turning off the power to the furnace a few times. That didn't work. Then at night, the fan was on and wouldn't turn off, so I unplugged the furnace. The next day, I tried reconnecting the wires while the power was off and then plugged it back in. Power was restored to Y1, so I thought I fixed it. Then about an hour later, I got the warning again. This is 100% repeatable. If I unplug the furnace then reconnect the Y1 wire, it works for about an hour then gives me the warning again. This makes me think there's a maintenance issue with the furnace. I'll have to clear a bunch of stuff out of the garage to get to it, so I haven't opened it up yet. Before I do, I was hoping to get a better idea what I should look for to troubleshoot it.