'C' wire issue for ecobee smart thermostat

[ctuser1]

I have an ecobee smart thermostat that controls both the AC and the Gas Boiler (Zone 1). The 'C' wire of this thermostat was fished through the walls from the AC Air Handler in the attic.

Because of this configuration, if I turn the AC unit off any reason (e.g. to winterize, like I see a lot of our neighbors do), the thermostat turns off and I lose heat in our main living area.

The other heating zone (downstairs, Zone 2, there is no direct AC there) has the C wire coming from the Gas Boiler. Boiler never needs to be turned off, so this is not an issue.

It isn't feasible to fish a new wire through from the boiler to upstairs thermostat. There are lots of walls in the way and it will be quite labor intensive (==expensive) even if it is possible.

Have you ever faced this problem? Should I just winterize (== cover up the compressor with a tarp so that it doesn't get snowed on) while the power is still on?

Or do you have any creative solution/suggestion?

[norajean]

If by winterize the AC you mean cover, I would probably skip it. The unit is designed to be outside. Covers can trap moisture. If someone turns it on in spring with the cover in place it may fry it. If you do cover it, shut off the circuit at the fuse box or outside if the connection box has a switch.

[Cadman]

I'm pro-cover, if you can cut power. Do you have an outdoor disconnect that feeds the A/C condenser? That's as good a place as any to kill power to the compressor/motor, and shouldn't affect the air handler transformer.

[HumanAfterAll]

I don’t have direct experience, but I thought the ecobee came with a 24v power adapter for this situation. Would that work for you?
https://support.ecobee.com/hc/en-us/articles/360009155051-Installing-your-ecobee-thermostat-with-the-Power-Extender-Kit-no-C-wire-

[ctuser1]

I don’t have direct experience, but I thought the ecobee came with a 24v power adapter for this situation. Would that work for you?
https://support.ecobee.com/hc/en-us/articles/360009155051-Installing-your-ecobee-thermostat-with-the-Power-Extender-Kit-no-C-wire-

It did. I ebay'ed it off because I thought I didn't need them. :-(..

They are also problematic. They do "power stealing". This tends to be a problem when/if the gas boiler, for example, is not turning on during the summer for a long time (i.e. there is no power to "steal"), with many unpredictable results like rapidly cycling through.

After reading these reviews online I wanted nothing to do with them.

[ctuser1]

I'm pro-cover, if you can cut power. Do you have an outdoor disconnect that feeds the A/C condenser? That's as good a place as any to kill power to the compressor/motor, and shouldn't affect the air handler transformer.

I found something that might work.

In the breaker box, there seem to be three slots dedicated to the entire HVAC setup. Slots 6 and 8 are controlled by a double breaker, where the chicken-scratch feels like the word "compressor". The air handler is slot 10.

(The slot numbers increment by 2, the odd numbered slots are in a different row).

I just turned the double breaker off.

The thermostat has a battery. Let's see if it continues to get power through the day and I will know by tomorrow if my maneuver is a success or not.

------------

Trying to decipher what looks like hieroglyphic script on the breaker box prompted me to do something anti-mustachian - order a $19.99 label maker from Amazon. I really need to label these guys better.

[ctuser1]

Thermostat is still on, 24 hours after turning off the double breaker.

So I think I am good. :-)

[ctuser1]

I'm happy to report that the (obvious in hindsight) solution of leaving the air handler on while turning off the compressor seems to be working.

The ecobee upstairs is still working.