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I've heard that before too. Would something like this add a wire thing off Amazon remedy the problem? Venstar ACC0410 Add-A-Wire Accessory for All 24 VAC Thermostats (4 to 5 Wires), White [link]
I have a 4 wire system that I converted into a 6 wire system by using two of these:
Venstar ACC0410 Add-A-Wire Accessory for All 24 VAC Thermostats (4 to 5 Wires), White [link]
I had this installed before the EcoBee when I had a Nest. They were a lot cheaper when I bought them tho.
Yeah, there was a risk of that happening since Ecobee does claim the PEK won't work with dual transformer systems.
That still leaves you with a couple of options. The one that Ecobee suggests in that article is simply using your current G wire as a C wire. This would mean that you would lose control over the fan so you wouldn't be able to run it independent of heating or cooling. The jumper wire between G and Y at the air handler is to ensure that the fan continues to work while the A/C is running.
If you want to still have independent control over the fan, the Venstar Add-A-Wire should work for you.
Pulling a new cable using the old cable is problematic in most homes if you don't have access to the cable at every point. Either it will be stapled, or it will be passing around too many tight bends with high friction.
There are some alternatives:
1. The new thermostat doesn't necessarily have to go in the same place as the old thermostat. Maybe there's an alternative location in your house that's a lot easier to pull a wire through to, and still reasonably placed for central temperature sensing.
2. You can buy no-C-wire add-on solutions like the Venstar units (e.g., [link]). They basically re-purpose one of the control lines as a C wire, and then use special signalling to create a virtual control line at a receiver that mounts behind the thermostat.
3. You can install an independent 24vac power supply (110v-to-24v ac transformer) closer to the thermostat. The sole purpose of the C wire is to provide 24vac power to the thermostat. You don't necessarily have to run that power all the way from the furnace/ac.
I have had an issue with the Nest and the problem was solved by installing a C-wire between the furnace and Nest. If you do not have a spare sixth wire going between your thermostat and your furnace, you can:
I have had a very similar experience to you and the problem was solved by installing a C-wire between the furnace and Nest. If you do not have a spare fifth wire going between your thermostat and your furnace, you can:
You can buy an Add-A-Wire kit so you can make your 5 wires into 6. This will allow you to have separate wires for the heating stages while also keeping your C-wire. I've never used the kit myself but it has good reviews.
Interesting. Either way, installing a C-wire usually fixes these issues. If you do not have a spare fifth wire going between your thermostat and your furnace, you can:
6 wire is pretty new, it is just that it came at a weird time. WIFI was just coming around to thermostats so no one was really getting geared up for it, but two stage heat exchangers were on the market and needed an extra wire known as the common wire. Then of course WIFI hit and units needed a constant power draw that the common wire did not provide so it changed to 7, 8, or ten wire depending on the system and what people wanted it to do.
If you go with a nest and it pulses the fan get an add a wire kit. There are other ways around it using jumper wires though, depends on how nerdy you want to get with this stuff.
Have this same setup and have constantly had voltage issues. “adD A C wiRe” crowd doesn’t seem to understand not everyone is an electrician, hvac specialist or can run new wires. I’m in a 90 yo house it’s not that fuckin simple.
Nest did just start selling their own C Wire solution that’s easy to install. Mine just arrived today.
I have previously used a Venstar add a wire kit with success on my upstairs unit that had more issues, but held off with my downstairs unit because when heat was on I had very few issues, which is most of the year since my heat is radiant via a boiler. Only the summer months do I get power issues with cool only on my cooling unit to the nest.
Is this the one?
This is what I used to add a C wire. It was easy.
Yes, but yikes don't pay that much. Hopefully you can see this one
This worked for me to get power without running an extra wire or using a transformer.
Venstar ACC0410 Add-A-Wire Accessory for All 24 VAC Thermostats (4 to 5 Wires), White
Learn more: [link]
You can install one of these https://www.amazon.com/Venstar-ACC0410-Wire-Accessory-Thermostats/dp/B01IF3QXMC/ref=sr_1_3?crid=B54T58WUO46V&dchild=1&keywords=venstar+add-a-wire&qid=1609730914&sprefix=venstar+a%2Caps%2C217&sr=8-3
You can go this route which worked for me at my house. Been running it for 4 years with no issue.
I originally had my 2gen for 7yrs until the battery crapped out (note: I ran w/o C wire for many yrs just fine).
I was going to change the battery (not reliable) but said screw it... and bought a newer 3rd Gen
I read up on it and it appears that w/o the C wire, the Nest thermostat battery will ONLY recharge only the system is on (heat or AC). I don't turn on my system that much so my battery wasn't charging and/or it was going through too many recharge cycles which I think I read hurts the battery in the long term. I've also read that sometimes Nest thermostats would act funny without a C wire.
I was just about to buy a transformer (see below) but I found my C wire deep in the wall and connected it. And I'm getting a very good voltage to the Nest (in "Techincal Info")
If I were you I would look into the following:
Addon C Wire or this Transformer which plugs into the wall and will supply your thermostat with power all the time.
Tl;dr Always try running a C wire to the Nest Thermostat; there are a few options. I'm no engineer though
I used this to add power to Nest in old house that wasn't getting quite enough power to stay charged. Worked fine for the two years we lived in house after installation (hope it's still working for new owner)
This will save your batteries:
I need a sixth wire for Y2 but don’t have one available so wondering if I purchase the Venstar add a wire:
Will this allow me to get the sixth wire?
To get a "C" wire to the nest:
This is a free way to do it:
This way is less than $30:
Here is a diagram I made awhile back to get rid of that power error with boiler & A/C:
(If you do the free g to c swap just ignore the g wire in the diagram)
Relay from diagram:
(Installing the Relay at boiler is easiest way)
Amazon has one for $25. God knows when you'll get it though.
To me it sounds like you need this: [link]
Also use this as a guide: [link]
Edit: Reason I say so is you should always use a common wire with Nest. You have to check your furnace terminal to see if it has a the right setup.
Or you buy this and watch the video that they have that goes into details. From the details you've listed at the bottom that this is the fix
Thinking about this some more the best solution would be to pull a new thermostat cable so you could have a real C wire. Or use an add-a-wire like [link] or [link] Or do the classic and use one wire for G and Y - move the green to C at both the boiler and Nest then put the yellow/white that has the wire nut under the G terminal at the boiler.
Otherwise more complicated would be add an isolation relay as in [link].
As a last resort if the wire/cable is stuck and can't be replaced then you can go the add-a-wire route. You might need to drill a 1/2 hole below the current hole to stuff the diode and wire nut into.
If you can, stop and go open the panel on your hvac system (Attic/garage/Basement/crawlspace)
There you will find where those wires connect. take a picture, note it down.
There is a good chance that you could simply connect the C wire. There
Or use a c-wire bypass