Tstat 24V Power From Where?

jrn8265 · Post by **jrn8265** » Tue. Jan. 06, 2015 10:37 am

My current tstat uses aa batteries and has two wires out to my Keystoker koker.

I want to replace it with a 24vt Insteon tstat.

Anybody know exactly how and from where I would wire the 24vt power to it since it has no batteries?

I guess I would have to run more wires to the tstat also for the voltage?

Novice here so any specifics would be appreciated!

Thank you!

McGiever · Post by **McGiever** » Tue. Jan. 06, 2015 11:07 am

jrn8265 wrote:My current tstat uses aa batteries and has two wires out to my Keystoker koker.

I want to replace it with a 24vt Insteon tstat.

Anybody know exactly how and from where I would wire the 24vt power to it since it has no batteries?

I guess I would have to run more wires to the tstat also for the voltage?

Novice here so any specifics would be appreciated!

Thank you!

http://www.insteon.com/thermostats

No wiring info in the directions?

The battery only is for the lighted display, Koker is the source for 24 vac to run stoker.
This is not a cut and dried subject.
Some t-stats can "scavage" the 24 volt for no battery operation, but more commonly it takes a 3rd wire at the t-stat.
But if adding more wires, I for vote 5 or better yet 7 wires for any chance of adding A/C someday.

jrn8265 · Post by **jrn8265** » Tue. Jan. 06, 2015 12:18 pm

Thanks much,

any idea where on the koker I get the 24vt?

McGiever · Post by **McGiever** » Tue. Jan. 06, 2015 2:54 pm

jrn8265 wrote:Thanks much,

any idea where on the koker I get the 24vt?

The battery is only for your original T-stat's display and settings memory...so the Koker's 2 wire hook-up to the t-stat IS coming from the Koker's 24 volt source.

You have a Honeywell RA 89A relay, and it is powered by a separate 24 transformer mounted somewhere and connected to 120 vac at or on a junction box near the relay, I'd imagine.

Look for the transformer it will have 2 connection on one side, colors may be blue and yellow or red and white that's the low voltage 24 vac side they are different colors depending on brand.
Now on the other side (may be inside the junction box) you will have several wires (4) white orange black red (2 wires used and 2 other wires are capped). Anyhow, that's the high voltage 120 vac side (keystoker has already wired 120 vac for you at factory).
Back on the 2 wire side (24vac) one (either blue or yellow) will be power and the other will be common this common is the connection point for the 3rd wire you need to add to the the t-stat, it would be C and usually is black. The 2 wires already existing at t-stat would be the R and W, (red & white) but still work if is different colors.

Recap: At new t-stat need to add a 3rd wire from/to 24vac transformer, it is wire "C".
3 wires= R,W,C. You will NOT need t-stat battery ever again.

https://customer.honeywell.com/resources/techlit/ ... 0-2481.pdf

jrn8265 · Post by **jrn8265** » Wed. Jan. 07, 2015 7:38 am

Thank you very much for taking your time to draw this out for me!

Vampiro · Post by **Vampiro** » Sun. Jan. 25, 2015 11:14 pm

If you need to transform your two wire system to a three wire system, and ARGO IR882 isolation relay is an awesome choice to upgrade any thermostat. I just purchased one, and wired it last night. It requires 24 VAC power from an external transformer which powers the board. The R & W wires go to X1 & X1 terminals which are normally open. The Wires that are going to go to the thermostat come out R W & C from the board, of which the C wire provides constant power to the smart thermostat.

The thermostat I have installed is an Ecobee. It is awesome. The isolation relay helped out tremendously, and was easy to tackle. When I get a chance I will be updating my Ecobee post, and other post with boiler and thermostat pictures.